A Pocket Guide to Birds of Galápagos 0691233632, 9780691233635

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A Pocket Guide to

Birds of Galápagos

Text: © 2022 by Tui De Roy Photographs: © 2022 by Tui De Roy / Roving Tortoise Worldwide Nature Photography, or by individual photographers where so indicated. Layout, maps, typeset & design copyright © Mark Jones / Roving Tortoise Books, Takaka, Golden Bay, New Zealand. www.rovingtortoise.com www.tuideroy.com www.galapagosconsultant.com Princeton University Press is committed to the protection of copyright and the intellectual property our authors entrust to us. Copyright promotes the progress and integrity of knowledge. Thank you for supporting free speech and the global exchange of ideas by purchasing an authorized edition of this book. If you wish to reproduce or distribute any part of it in any form, please obtain permission. Requests for permission to reproduce material from this work should be sent to: [email protected] Published by Princeton University Press, 41 William Street, Princeton, New Jersey 08540 99 Banbury Road, Oxford OX2 6JX press.princeton.edu All Rights Reserved ISBN (pbk.) 978-0-691-23363-5 ISBN (e-book) 978-0-691-23364-2 Library of Congress Control Number: 2022930882 British Library Cataloging-in-Publication Data is available Printed on acid-free paper. ∞ Printed in Italy 1 3 5 7 9 10 8 6 4 2

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A Pocket Guide to

Birds of Galápagos Tui De Roy

Princeton University Press Princeton & Oxford

3

Contents Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Maps: Geographic setting . . . . . . . . . . . . . . . . . . 10–11 Physical and climatic setting . . . . . . . . . 12–13

Part 1: Land Birds . . . . . . . . . . . . . . . . . 15 The dangers of being unique . . . . . . . . . 16–17 Galápagos Hawk † † . . . . . . . . . . . . . . . . . . . . . . . 18 Short-eared Owl † . . . . . . . . . . . . . . . . . . . . . . . . 20 Barn Owl † . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Mockingbirds: Darwin’s inspiration . . . 24–25 Galápagos Mockingbird † † . . . . . . . . . . . . . . . 26 San Cristóbal Mockingbird † † . . . . . . . . . . . . 27 Española Mockingbird † † . . . . . . . . . . . . . . . . 28 Floreana Mockingbird † † . . . . . . . . . . . . . . . . 29 Yellow Warbler † . . . . . . . . . . . . . . . . . . . . . . . . . 30 Galápagos Flycatcher † † . . . . . . . . . . . . . . . . . . . 31 Darwin’s Flycatcher † † . . . . . . . . . . . . . . . . . . . . 32 Galápagos Dove † † . . . . . . . . . . . . . . . . . . . . . . . 34 Dark-billed Cuckoo . . . . . . . . . . . . . . . . . . . . . . . 36 Galápagos Martin † † . . . . . . . . . . . . . . . . . . . . . . 37 Feral Chicken . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Smooth-billed Ani . . . . . . . . . . . . . . . . . . . . . . . 39

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Darwin’s Finches explained . . . . . . . . . . 40–47 Small Ground Finch † † . . . . . . . . . . . . . . . . . . 48 Medium Ground Finch † † . . . . . . . . . . . . . . . . 49 Large Ground Finch † † . . . . . . . . . . . . . . . . . . . 50 Sharp-beaked Ground Finch † † . . . . . . . . . . . 52 Genovesa Ground Finch † † . . . . . . . . . . . . . . . 53 Vampire Finch † † . . . . . . . . . . . . . . . . . . . . . . . 54 Common Cactus Finch † † . . . . . . . . . . . . . . . . 56 Española Ground Finch † † . . . . . . . . . . . . . . . 58 Genovesa Cactus Finch † † . . . . . . . . . . . . . . . 59 Small Tree Finch † † . . . . . . . . . . . . . . . . . . . . . 60 Medium Tree Finch † † . . . . . . . . . . . . . . . . . . . 61 Large Tree Finch † † . . . . . . . . . . . . . . . . . . . . . 62 Mangrove Finch † † . . . . . . . . . . . . . . . . . . . . . . 63 Woodpecker Finch † † . . . . . . . . . . . . . . . . . . . 64 Vegetarian Finch † † . . . . . . . . . . . . . . . . . . . . . 66 Green Warbler Finch † † . . . . . . . . . . . . . . . . . . 68 Gray Warbler Finch † † . . . . . . . . . . . . . . . . . . . 69 ††

†

Species truly endemic to Galápagos (35 of 63 resident birds). Considered endemic subspecies by some authors (an additional 10).

The Flightless Cormorant of Galápagos is the largest and heaviest of all cormorants, having traded flying abilities for extra diving capacity — recorded down to 70 m (230 ft). They always dry their useless wings between fishing trips; it is, however, rare to see a whole group doing so simultaneously.

Part 2: Seabirds . . . . . . . . . . . . . . . . . . . 71 Endemic or Not? . . . . . . . . . . . . . . . . . . . 72–73 Galápagos Penguin † † . . . . . . . . . . . . . . . . . . . . . 74 Waved Albatross † † . . . . . . . . . . . . . . . . . . . . . . . 76 Galápagos Petrel † † . . . . . . . . . . . . . . . . . . . . . . . 78 Galápagos Shearwater † † . . . . . . . . . . . . . . . . . 79 White-vented Storm Petrel † . . . . . . . . . . . . . . 80 Wedge-rumped Storm Petrel † . . . . . . . . . . . . . 82 Band-rumped Storm Petrel . . . . . . . . . . . . . . . 83 Blue-footed Booby . . . . . . . . . . . . . . . . . . . . . . . 84 Red-footed Booby . . . . . . . . . . . . . . . . . . . . . . . 86 Nazca Booby . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 Great Frigatebird . . . . . . . . . . . . . . . . . . . . . . . . 90 Magnificent Frigatebird . . . . . . . . . . . . . . . . . . . 92 Flightless Cormorant † † . . . . . . . . . . . . . . . . . . . 94 Red-billed Tropicbird . . . . . . . . . . . . . . . . . . . . . 96 Brown Pelican † . . . . . . . . . . . . . . . . . . . . . . . . . . 98 Swallow-tailed Gull † † . . . . . . . . . . . . . . . . . . . 100 Lava Gull † † . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 Sooty Tern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 Brown Noddy † . . . . . . . . . . . . . . . . . . . . . . . . . 105

Part 3: Waders and Migrants . . . . . . 107 Great Blue Heron † . . . . . . . . . . . . . . . . . . . . . . 108 Yellow-crowned Night Heron † . . . . . . . . . . . . 110 Lava Heron † † . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Great Egret . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cattle Egret . . . . . . . . . . . . . . . . . . . . . . . . . . . . American Flamingo . . . . . . . . . . . . . . . . . . . . . Paint-billed Crake . . . . . . . . . . . . . . . . . . . . . . . Common Gallinule . . . . . . . . . . . . . . . . . . . . . . Galápagos Rail † † . . . . . . . . . . . . . . . . . . . . . . . . White-cheeked Pintail † . . . . . . . . . . . . . . . . . American Oystercatcher . . . . . . . . . . . . . . . . . Black-necked Stilt . . . . . . . . . . . . . . . . . . . . . .

112 113 114 116 117 118 120 122 123

Visitors from afar . . . . . . . . . . . . . . . . . 124–125 Whimbrel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wandering Tattler . . . . . . . . . . . . . . . . . . . . . . Ruddy Turnstone . . . . . . . . . . . . . . . . . . . . . . . Willet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lesser Yellowlegs . . . . . . . . . . . . . . . . . . . . . . . Semipalmated Plover . . . . . . . . . . . . . . . . . . . Black-bellied Plover . . . . . . . . . . . . . . . . . . . . . White-rumped Sandpiper . . . . . . . . . . . . . . . . Sanderling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Spotted Sandpiper . . . . . . . . . . . . . . . . . . . . . . Least Sandpiper . . . . . . . . . . . . . . . . . . . . . . . . Phalaropes (3 species) . . . . . . . . . . . . . . . . . . Migrant Gulls (3 species) . . . . . . . . . . . . . . . . . Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

126 126 127 127 127 128 128 128 129 129 129 130 131 133

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . 134–135 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . 136

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A pair of Medium Ground Finches (Geospiza fortis) visit an Opuntia cactus flower, but their bills are not designed to take advantage of this food source.

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Finch photo: © P.R. Grant and B.R. Grant.

Called “Big Bird,” this juvenile Darwin’s Finch represents a very successful lineage discovered on Daphne Islet by the Grants in 1981, which they believe to result from hybridization between a Medium Ground Finch and a Common Cactus Finch (Geospiza fortis and G. scandens). Heavier and more successful in the Daphne environment than either species, descendants have bred only with each other, producing seven generations over 30 years.

Foreword Several guidebooks have been written about Galápagos birds and other animals, and the standard of photography and production has increased enormously over the last few decades, but this book by Tui De Roy is the gold standard against which all others should be compared. Nobody knows the extraordinary Galápagos wildlife as well as she does. Tui grew up in Galápagos, fascinated by the natural world and curious about the lives of animals. She traveled throughout the archipelago and saw different species from the ones on her home island of Santa Cruz. She photographed them and became so skilled she developed an international reputation as an excellent naturalist-photographer. This book is the product of a lifetime of absorption in the natural history of Galápagos. We first met Tui as a barefoot girl while carrying out our lifelong study of Darwin’s Finches on Daphne Islet, research which would reveal the real-time process of natural selection that drives the evolution and diversification of this iconic group of Galápagos land birds. During this study we were fortunate to observe the rare formation of a new lineage by the hybridization of two species, and to visualize this as one way in which new species may have formed in the past.

Daphne Islet at sunrise, the nucleus of

Darwin’s Finch evolutionary studies. A visitor to the islands with an interest in nature wants to know not only the names of the birds and how to identify them, but also what distinguishes them, and how they differ in behavior. Within these pages you have a guided tour. The photographs show various images of all the resident bird species, plus some migrants, in their natural habitat, feeding, courting or just being. The text provides everything else in short informative summaries that will be invaluable for identification. In combination, the photographs and text are an invitation to obtain the maximum benefit and enjoyment from looking at nature on a short visit to these unique, enchanted and protected isles.

Peter & Rosemary Grant Drs. Peter and Rosemary Grant, FRS, FRSC, are British evolutionary biologists with lifelong careers studying evolution in Darwin’s Finches at a fine-grained level, proving that the adaptation process can be measured in real time. Both are emeritus professors at Princeton University.

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Introduction

How to use this book

Coming in to land with feet held high and whistling loudly, a male Blue-footed Booby performs a spectacular courtship display called a “landing salute.”

Birds, the direct descendants of dinosaurs, touch our lives in a million ways, whether we are aware of it or not. In Galápagos, with just 63 resident species, the list is short, but their ubiquitous presence takes on a very special twist: they show us the ways of natural selection and demonstrate the evolution of species better than anywhere else in the world. They also lead fascinating lives that are, in most cases, very easy to observe. This is why I opted not only to make this a bird identification guide, but to provide as much information as possible on their behavior and ecology. To make finding each species easy in this pocket guide, I chose not to follow a strict taxonomic order, but rather to group different types of birds by their habits and the habitat in which they are most likely seen. The Galápagos Archipelago is a little world unto itself. Despite the islands’ much-celebrated reptilian fauna, the birds here are at the center of that world and are well worth long and detailed observation.

Land birds

Of the 32 truly terrestrial birds of Galápagos (including two introduced species), a staggering 26 are found nowhere else in the world, while three more, both owls and the Yellow Warbler, hang in the balance between subspecies and species — where appropriate, a qualifying double dagger sign ‡ ‡ (e.g., Endemic ‡ ‡) refers the reader to more specific details within the text. Of this remarkable collection, there is no doubt that the motley, dull-colored group collectively known as Darwin’s Finches steal the show. What these tanager descendants lack in flamboyance they make up in the extraordinary influence they’ve brought to bear on scientific thinking. For this reason, I have dedicated a large portion of this book to all 17 Darwin’s Finches (formerly reported as 14), not only because they are the most difficult to correctly identify, but also because they represent a kind of living natural experiment. Drs. Peter and Rosemary Grant, who wrote the foreword to this book, have spent their lifetime studying the evolution of these little birds and have been able to demonstrate in real time how species adapt and change in response to natural selection. More recently, behaviorist Dr. Sabine Tebbich added that Darwin’s Finches, as a group, “are the most inventive of all small birds in the world.” That’s a big statement for those “little brown jobs” that so many Galápagos visitors overlook. But this is what extreme isolation does Brightly colored in his prime breeding plumage, a male Yellow Warbler busily picks insects on a coralline beach (San Cristóbal). 8

to birds stranded on an archipelago, confronted with a whole spectrum of new ecological opportunities to explore, and few predators to contend with: they evolve, sometimes right in front of our eyes, in real time.

Seabirds

For the marine birds of Galápagos, the panorama is of course very different from their terrestrial counterparts, as many find themselves at home on the ocean, using land only as a convenience to roost, or a necessity to breed. For them, it is the unique oceanographic setting governing marine productivity that makes Galápagos unique. Some, like the Galápagos Penguin, Flightless Cormorant and Lava Gull, may spend their entire lives never venturing out of sight of land, but others range for thousands of miles on every feeding trip, as is the case for the Waved Albatross or Galápagos Petrel. Some land birds and seabirds even interact in startling ways, such as the Vampire Finch drinking the blood of boobies, or owls catching petrels.

Waders, shorebirds and migrants

With standing water limited to saline lagoons and irregular vernal pools, it should come as no surprise that the diversity of species using these habitats is much more restricted than the previous categories. They are generally divided into two habitat groups: herons and egrets frequenting mostly mangrove inlets; and flamingos, ducks, crakes and gallinules ranging from hyper-saline to brackish and, rarely, freshwater ponds. A notable exception is the Galápagos Rail, which favors moist understory but does not require standing water and could arguably be regarded as a land bird. In the absence of estuaries or extensive mudflats, only two genuine shorebirds, the Black-necked Stilt and American Oystercatcher, are resident, both species ranging widely in the Americas. However, they are often joined by a variety of migrants and vagrants, but only a small list can be seen with any regularity and are therefore treated as a sub-section towards the end of this book.

Maps

I feel strongly that detailed physical maps and explanations depicting both the geography and habitat are key to understanding bird distribution within the islands, which I have provided at the beginning of this book. For land birds, precise distribution maps are also crucial and can often help in narrowing down species, especially in Darwin’s Finches, many of which are restricted to certain islands. On the other hand, seabirds, waders and shorebirds in many cases are omnipresent throughout the islands, but with nesting colonies in fixed locations. For these I have provided one large-scale map, with range (penguins and cormorants) and coded hexagons for principal seabird colony The four endemic locations. Some species, however, nest opportunistically species of Galápagos wherever conducive habitat is available along most shorelines mockingbirds were or salt lagoons, e.g., pelicans, oystercatchers, stilts, instrumental flamingos, Lava Gulls, etc. In these cases, I have provided in stimulating only range information within the species descriptions. Charles Darwin

Glossary

Inevitably in a compact guidebook it is necessary to condense standard syntax and to use a few technical terms not common in everyday language. I have therefore included a brief glossary of expressions and words that may not be familiar to the lay reader. Comparable metric / US customary units are used throughout the book. Above: Just before hitting the water at speeds reaching almost 100 km/h (60 mph), a plunge diving Blue-footed Booby extends its wings to create a perfect arrow shape for an almost splash-free entry.

to ponder and formulate his revolutionary theories on natural selection.

9

92° W

91° 30’ W

Darwin

1° 30’ N

167 m / 548 ft

5

6

7

91° W

90° 30’ W

90° W

9 10 11 90° W

Wolf

5

253 m / 830 ft

1° N

6

7

8

9 10

5° N

Galápagos Islands

EA ST ERN T R OPI CAL PA CI F I C O CE A N

0° Galápagos Platform

Pinta

10

EASTERN TROPIC PA C I F I C O C E A N

777 m / 2,549 ft

0° 30’ N

Marchena Roca Redonda 3

0°

4

Tagus Cove

905 m / 2,969 ft

V. Darwin 1,280 m 4,200 ft

1,463 m / 4,800 ft

2

4

V. Cerro Azul 1,676 m 5,499 ft

V. Sierra Negra 1,137 m 3,730 ft

Puerto Villamil

0

10 mi

100 km

30 nm 30 mi

50 nm 50 mi

8

9 10

4

2

458 m / 1,503 ft

Santa Cruz 864 m / 2,835 ft

4

Puerto Ayora

9

Santa Fe 244 m / 801 ft

Tortuga 6 8

4

50 km

9 10

Plazas 9 10

Punta Cormorant

= Roads servicing inhabited areas

10

Baltra

4

Galápagos Platform

Caleta Iguana

10 nm

12

Rábida

367 m / 1,204 ft

Daphne 4

Seymour 4 7 Mosquera

Pinzón

Isabela

10 km

Bartolomé

2

V. Alcedo 1,097 m 3,599 ft

0° 30’ S

0

6 7 9 10

Santiago

V. Wolf 1,707 m 5,600 ft

Fernandina

0

5 8

Galápagos Islands

4

1° S

3

64 m / 210 ft

Cabo Marshall

V. Ecuador 790 m 2,592 ft

Equator

Genovesa

343 m / 1,125 ft

9 10

12

Puerto Velasco Ibarra

Floreana

640 m / 2,100 ft

Champion 9 10 5

6

Gardner 7 8 9 10

6

Puerto Baquerizo Moreno

89° W

Panamá

Cocos Island

80° W

Malpelo Island 6 10

Colombia

H Quito

Isla de la Plata 1

Guayaquil

Ecuador

CAL N

Perú 0° 30’ N elevation 1,707 m 5,600 ft 1,500 m 4,900 ft 1,250 m 4,100 ft 1,000 m 3,300 ft 750 m 2,450 ft 500 m 1,650 ft 250 m 800 ft 100 m 330 ft 50 m 165 ft 0 0 - 200 m - 650 ft - 500 m - 1,650 ft - 750 m - 2,450 ft - 1,000 m - 3,300 ft - 1,500 m - 4,900 ft - 2,000 m - 6,500 ft - 2,500 m - 8,200 ft - 3,000 m - 8,800 ft - 3,500 m -11,500 ft - 3,650 m -12,000 ft bathymetry

3

4 Punta Pitt 7

León Dormido 6 8

5 6 8 10

0°

Equator

0° 30’ S

8 2

★

San Cristóbal 696 m / 2,284 ft

1° S

Española 1

198 m / 650 ft

4

6

7

9 10

Gardner 1° 30’ S

MAP CREDITS: Base map: Wikimedia Commons Attribution-ShareAlike 3.0 International (CC BY-SA 3.0) — Filename: Galápagos_Islands_topographic_map-blank.png: by Eric Gaba for Wikimedia. Image Description: UTM projection, WGS84 datum; Topo scale: 1:800,000 (precision 200m); Bathy scale: 1:4,000,000 (precision 1,000m). Sources: Topography: NASA SRTM3 v2; Bathymetry: William Chadwick, Oregon State University. Inset: Screenshot from NASA EOSDIS v1.62.3 EarthData. Design, overlays, titling, etc.: © Mark Jones, Roving Tortoise Books, New Zealand. Note: Place names are those in common use, and a mix of Spanish (primarily) and English languages; they are not necessarily the official names gazetted in Ecuadorian Military Geographical Institute publications.

89° 30’ W

Costa Rica

Geographic setting

With seabird breeding distributions

This map of the entire archipelago, including elevation contours both above and below sea level — along with the inset to show the broader geographical context — clearly depicts the Galápagos as a cluster of oceanic islands with no link to Central or South America. Instead, they are the product of a magmatic thermal plume deeply rooted in the earth’s mantle, known to geologists as a volcanic “hotspot.” Active for untold millions of years, this hotspot has produced a bulge in the seafloor known as the undersea Galápagos Platform. Meanwhile, the Nazca Plate (itself the result of tectonic forces breaking up the earth’s crust) drifts slowly southeast and plunges steeply beneath the South American Continental Plate, carrying with it the oldest islands. These dead or dying volcanoes slowly sink into the sea as they slide off the Platform bulge and are gradually replaced by newer, more active islands in the west, characterized today by the massive, basalt lava-streaked shield volcanoes of Isabela and Fernandina Islands, relatively freshly risen from the deep ocean. Below sea level, these imposing structures also serve to drive the cold waters of the Cromwell Current to the surface, as they arrive, nutrient laden, through deep ocean layers from the west. This phenomenon has produced a unique microclimate where penguins and flightless cormorants thrive. In addition, the isolation of both the archipelago, and each island within it, has produced the perfect melting pot for the extraordinary level of adaptations and endemism seen in the avifauna of Galápagos. The hexagonal number badges (primary nesting sites) and dotted or hashed Principal seabird colony locations lines (limited ranges and main Galápagos Penguin (p. 74–75) sites of flightless 1 Waved Albatross (p. 76–77) 2 Galápagos Petrel (p. 78) species) depict 3 Wedge-rumped Storm Petrel (p. 82) suitable breeding 4 Blue-footed Booby (p. 84–85) areas chosen by 5 Red-footed Booby (p. 86–87) respective seabird 6 Nazca Booby (p. 88–89) species, whose 7 Great Frigatebird (p. 90–91) locations reflect 8 Magnificent Frigatebird (p. 92–93) their proximity Flightless Cormorant (p. 94–95) to the preferred 9 Red-billed Tropicbird (p. 96–97) oceanic conditions 10 Swallow-tailed Gull (p. 100–101) that they rely on for 11 Sooty Tern (p. 104) 12 American Flamingo (p. 114–115) feeding.

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Physical Galápagos setting A unique climatic environment

Averaged over one month (September), daily global sea temperatures recorded by NASA clearly depict the remarkable patterns of cold waters around Galápagos. The deep ocean Cromwell Current upwelling locally from the west, together with cool, nutrient-rich waters brought from the south by the Humboldt and South Equatorial Currents, are the driving factors for the archipelago’s exceptional climate and singular marine ecosystem. Nowhere else on the globe do such cold water conditions regularly reach the equator. This unparalleled environment has given rise to a number of endemic seabird species, including some whose movements are exceedingly restricted (e.g., Galápagos Penguins and Flightless Cormorants), while others range far southward but return to the islands to breed (Waved Albatross, Galápagos Petrel, Swallow-tailed Gull). Whereas the high level of endemism in Galápagos land birds may be widely known, birders are often surprised at the uniqueness of their marine counterparts.

89 > 32

Panamá

North Equatorial Current North Equatorial Countercurrent Cromwell Current

w

lo

áF

m na

Colombia

Pa

*ITC

Z*

equator

(Pacific Equatorial Undercurrent)

Ecuador

South Equatorial Current

bo stal um Coa

H rú (Pe

Perú

nt rre t) Cu urren C

rú Pe ent

urr

ic C

st ea ds uth in So de W Tra

ean

Oc

12

ldt

* ITCZ * = Intertropical Convergence Zone

Globally, this represents the boundary line between the Northern and Southern Hemisphere climatic systems. Also known as the doldrums for its fickle winds and sudden thunderstorms, this shifting “climatic equator” moves up and down with the seasons, defining the wet and dry weather patterns that are characteristic of the tropics. As can be seen from the world view, the ITCZ is particularly well defined in the eastern tropical Pacific region around the Galápagos archipelago and is sharply demarcated by dramatically differing sea temperatures. From its northernmost position during the Northern Hemisphere autumn, it spreads southward during the winter months, temporarily displacing the typically cold waters that normally bathe the islands, as depicted here. Nowhere else in the oceans does this phenomenon occur so vigorously.

Chile

MAP CREDITS: Base maps: Multi-scale Ultra-high Resolution (MUR) Sea Surface Temperature data from NASA EOSDIS Physical Oceanography Distributed Active Archive Center (PO.DAAC); Opposite: NASA Satellite Imaging. All titling, ocean current overlays, etc.: Mark Jones, Roving Tortoise Books, New Zealand.

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Seasons on the equator As can be clearly appreciated on the NASA image below, the habitat for land birds is strongly governed by frequent volcanic activity, especially in the western islands, where large swaths of land are streaked with dark, quasi-lifeless lava flows. The second dominant factor stems from the seasonal shift in ocean currents, which divides the year roughly into two main seasons: the hot/rainy season, January–May, and the cold/dry season, June–December. Refining this further, the hot season rains, which can be torrential, are normally concentrated in a shorter period of one to two months around the middle of the hot/sunny half of the year. This is due to the seasonal slackening of southerly trade winds and currents allowing the much warmer waters from the Panamá region to flow southward through the archipelago. When the rains fall, the entire vegetated regions of the islands turn lush and green, from coast to summit (as seen below), spurring frenetic nesting activity in virtually all terrestrial bird species. Conversely, the warm seas, devoid of upwelling, are now nutrient poor, producing lean times for seabirds, who tend to disperse away from their nesting colonies. The cold and dry conditions return when the Southern Hemisphere winter takes over, reviving the steady southeast trade winds, and the strong, cold ocean currents and upwellings that these winds drive. Throughout this season, an even cloud layer caps the cold ocean almost continuously. Sitting at roughly 200–300 m (650–1,000 ft) elevation, the cool air mass is unable to rise by thermal convection, creating an inversion layer that traps moist air beneath it, devoid of precipitation. But there’s a caveat: while these cool, rainless conditions prevail in the coastal lowlands, the cloud bank meeting the slopes of the higher islands creates misty conditions with persistent drizzle, locally known as “garúa.” As a result, the highlands are characterized by cloud forests, whereas the lowlands are mostly arid semi-deserts that flush green for only a few weeks in the year. Further confounding this complex climatic condition, anomalous years are frequent: sometimes the warm northern waters don’t quite reach Galápagos, leaving the islands totally parched by the sun for months on end, while the seas Pinta Galápagos Islands remain relatively from Space cool. In other years, Marchena the warm seas may Genovesa flood down and stay for excessively long equator periods that may stretch right into the Santiago otherwise “cold” Bartolomé season, bringing hard Seymour times to all life forms Daphne Baltra dependent on cool, Rábida nutrient-rich seas. Fernandina Plazas These unpredictable Pinzón oscillations are San Cristóbal Santa Cruz termed respectively Santa Fe El Niño (hot) and La Niña (cold). NASA imaging clearly shows the islands’ more land bird–friendly vegetated zones in stark contrast to a mosaic of predominantly barren, younger lava flows.

Isabela

Floreana

Española 13

Migrant Raptors Peregrine Falcons (Falco peregrinus), and much more rarely, Ospreys (Pandion haliaetus), are the only two other diurnal raptors that may be seen in Galápagos from time to time, in addition to the endemic hawk.

Galápagos Hawks over Alcedo Volcano fumaroles: Pale-colored juveniles band together in groups that roam in search of prey, using their numbers to overwhelm the territories of aggressive adults before moving on. They can be very bold and curious in areas where they rarely see humans.

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Part 1

Land Birds

15

Introduced predators When humans arrived on the islands, a cohort of alien mammals such as rats, cats, pigs and dogs were introduced into the vulnerable ecosystems, depleting populations of some ground-nesting birds like doves and rails.

Darwin’s Finches mixed flock: Despite their specially shaped beaks, each developed to optimally exploit a distinct food source, different finch species often flock together and share food resources whenever the chance arises. Three species can be seen here: Small, Medium (with variablesized beaks), and Large Ground Finches (Santa Cruz Island).

Natural predators Aside from better-known predation by hawks and owls, Galápagos snakes and giant centipedes are also predators of nestlings even in finch nests that look inaccessible.

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The dangers of being unique Avian pox Generally speaking, endemic Galápagos land birds are tough and adaptable — that’s why they did so well under rugged island conditions. But, with the arrival of humans, evolving in isolation also made them vulnerable to unexpected threats. For example, the Galápagos Hawk (previous pages), being top predator, feared nothing and so was unprepared for the wrath of farmers whose poultry they relish, leading to their local extermination on inhabited islands. For smaller species, the biggest threat stems from introduced parasites and pathogens such as avian pox, which affects mainly fledglings, and against which they have very low defenses. The good news is that circumstantial evidence points toward increasing resistance to the virus, with increased fledgling survival in the last decade.

Avian vampire fly The worst of the recently introduced bird pests is a fruiteating fly, Philornis downsi, whose larvae act as vampires in small birds’ nests, sucking blood from young chicks and often causing 100% mortality, especially in the smallest bird species. This is one area where the work of Charles Darwin Research Station scientists and Galápagos National Park managers is crucial to fighting back invaders with modern science and technologies. Dosing the nests with harmless insecticide can save the most threatened birds species, while a permanent biological control of the fly is being developed. 17

Galápagos Hawk Buteo galapagoensis Endemic

Juvenile. Immature head plumage.

Adult.

Identification • Unmistakable, largest and only fully diurnal raptor in Galápagos. • Adults mostly blotchy dark brown and black, with paler mottled underwings, bright yellow lore and legs. • Juveniles mottled pale brown with dark streaking. • Often very curious and may approach closely, especially juveniles. • Not to be confused with two rare visitors: Osprey (larger, paler and more slender wings) and Peregrine Falcon (smaller, pointed wings, faster flier). Adult (left) with juvenile, hunting insects disturbed by giant tortoise.

Status • Population stable and doing well on uninhabited islands. • Extirpated in the vicinity of human settlements (San Cristóbal, Santa Cruz, Floreana, southern Isabela) because of its propensity for taking farm poultry.

Wide distribution throughout most of the larger, uninhabited islands, except Genovesa.

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Natural History

Adult female carrying remains of marine iguana kill.

• A generalist raptor whose ancestor is believed to be the Swainson’s Hawk of North America. • Sedentary year-round, holding a large nesting and feeding territory. • Female considerably larger than male, mating in Juvenile in full practice stoop. “polyandric” group, with up to 8 subservient males all sharing equal status, mating, fiercely defending territory and feeding young. • Juveniles wander freely, often in a group, whereas adults defend large territories year-round. • May nest in large tree or on rocky promontory.

Special note This handsome raptor represents the top terrestrial predator in Galápagos. Found from coastlines to volcanic summits, Galápagos Hawks prey on a large variety of food items, including small birds, lizards, young turtles, tortoises and iguanas, large insects such as crickets, caterpillars and centipedes, plus occasionally carrion.

Typical nest site on rocky promontory with good lookout points all around.

Multi-year nest in fork of large palo santo tree, with adults feeding hatchling sea turtle to chicks; larger female on right.

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Short-eared Owl

Asio flammeus galapagoensis Endemic subspecies ‡ ‡ Natural History

Bringing mouse to nest in daytime.

Identification • A large, well-camouflaged owl that blends equally well in lava terrain and in dry vegetation. • May regularly be seen in broad daylight, or hunting at twilight. • Small “ears” often not specifically visible. Rarely are the small ear tufts visible. Galápagos subspecies is darker, making it well camouflaged in rugged lava fields, as when hunting in a storm petrel colony on an overcast day.

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• A somewhat generalist owl found in all Galápagos habitats, from barren lava shorelines and small islets to misty cloud forests. • Wide range of prey, from storm petrels caught in daylight to rodents at night. • Nests very rarely seen, on the ground, under dense vegetation. • Roosts under rocky overhangs or hidden in ground vegetation. Downy juvenile exploring surroundings of nest hidden in dense ferns.

Flying high over territory and calling in broad daylight.

Special note

Around inhabited areas traffic is a significant cause of mortality as owls often sit on the roadways, attracted by insects and rodents killed by passing vehicles.

One of the world’s most widespread owl species, found on all continents and many islands (except Australasia and Antarctica), with 10 or more subspecies identified. Galápagos form is likely to be a separate species, filling the ecological niche between the endemic hawk and the nocturnal Barn Owl. Preys on seabirds, land birds, and rodents, especially where Barn Owls are absent, such as on Floreana and Santa Fe. ‡‡

Highly adaptable, Short-eared Owls can be seen hunting by day or night. Cryptic coloration makes owls difficult to spot. Prefer hunting on the ground via a short pounce rather than in flight.

• Status • Widespread and fairly common on most islands. • Decreasing where introduced blackberry is rampant in understory. • Worldwide distribution, but Galápagos race genetically distinct.

Wide distribution throughout the entire archipelago.

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Barn Owl

Tyto alba punctatissima Endemic subspecies ‡ ‡

Hunting sequence: from far right to left, showing how acute hearing, helped by sound-focusing feathered facial disk, guides the owl to pounce on its prey (introduced house mouse), which is then carried to nest in its beak.

Identification • Classic feathered “facial disk” to reflect and focus on faint sounds is diagnostic. • The female is much darker than the male, with tiny white dots covering the cinnamon and gray mantle. • Seen mainly where rodent prey (endemic or introduced) is available. • Only active in full darkness, often flying over or alighting on roadways where rats are attracted to road-killed birds. • This secretive owl can sometimes be found roosting in the dim entrance of lava tubes.

Natural History • A solely nocturnal owl found mostly where rodents are plentiful. • Generally not present on low, dry islands. • Roosts and nests mainly in dimly lit natural spaces, at the entrance of dark caves and lava tubes, also sometimes in human-made structures. Female incubates eggs and guards chicks.

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Young chick, still blind, swallowing a complete rodent. Surrounded by rodent larder that is kept well stocked by the male.

Special note Considered the most globally widespread of all land birds, ranging on all continents except Antarctica, and numerous island groups. As many as 28 distinct subspecies have been proposed. The Galápagos type, Tyto alba punctatissima, is overall smaller and darker than Barn Owls found elsewhere and is likely a separate species. ‡ ‡

Male (left) is larger and paler than female.

Fledglings share a giant centipede brought by parents. This species feeds mainly on rodents and insects, rarely birds.

Status • Population stable and doing fine on several islands. • Disappeared from Floreana, for unexplained reasons. • Worldwide distribution with 28 recognized subspecies.

Widely distributed on many larger islands of the archipelago.

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The Mockingbirds Mimus spp. Darwin’s great source of inspiration When young Charles Darwin visited the Galápagos Islands in September 1835 aboard the HMS Beagle, it was not the finches (which now bear his name), but the subtle differences in the mockingbirds he collected that provided him with his first hint on the process of evolution. During his five-week stay he was able to observe three of the archipelago’s four species, enough for him to ponder the possibility that one ancestral form could diverge into separate types on different islands.

Battlefront tactics: Large neighboring family clans of Española Mockingbirds (one dominant pair with their adult offspring) form battle lines using ritualized “flick fighting” to demarcate territorial boundaries, flashing wings and tails, which may lead to no-holdsbarred individual tussles.

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Galápagos Mockingbird Mimus parvulus

San Cristóbal Mockingbird Mimus melanotus

Española Mockingbird Mimus macdonaldi

Floreana Mockingbird Mimus trifasciatus

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Galápagos Mockingbird Mimus parvulus

Song is long, clear and elaborate.

Endemic

Juvenile, with speckled breast, eating small fiddler crab.

Identification

Adult pairs are often seen together.

Natural History

• Conspicuous black, white and gray bird, frequently seen in pairs. • A very pedestrian bird, often walking over open ground rather than flying. • Occurs on all small and large islands, except the three southernmost, each with its own, unique species.

• A generalist, feeding mainly on the ground, taking berries, flowers, large insects and also carrion. • Intelligent and clever, it is adept at digging, turning over stones or peeling bark to uncover prey. • Very territorial, sings loudly from high perches and chases not only conspecifics, but also smaller birds. • Pairs work together much of the time, allowing one or two subservient young from the previous season to help in defending territories and feeding new chicks. • Uses all habitats, with preference for lowlands. Pair near their nest in Opuntia cactus crown.

Adult searching for insects beneath Opuntia cactus bark.

Status • Widespread, except southern islands with own species. • Population appears stable, although many juveniles badly affected by an introduced avian pox disease.

Widely distributed throughout the archipelago except Pinzón and three islands each with their own species.

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San Cristóbal Mockingbird Mimus melanotus

Endemic to San Cristóbal Island

Typical mottled back and black ear patch coloration; (below) adults are often seen singing loudly from center of territory.

Juvenile, with speckled breast, eating sap-sucking insect.

Identification • Similar to the more widespread Galápagos Mockingbird, but less contrasting pattern. • Slimmer than other three species, with slighter beak and legs.

Natural History • Occurs only on San Cristóbal Island, where it is common mainly throughout arid regions. • Similar habits as Galápagos Mockingbird. • The smallest and most arboreal of the four species. • Recent study shows that, instead of offspring helping parents as in other species, Feeding on sticky breeding units Cordia lutea (muyuyo) often consist of berries. two males paired with one female.

Status • Considered endangered due to limited range. • Common mostly in lowlands.

Distribution limited to San Cristóbal Island.

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Española Mockingbird Mimus macdonaldi Endemic to Española Island Eating Tribulus petals.

Submissive gestures by young “helper” defray any aggression.

Identification • Largest and boldest of all four species. • Considerable mottling, especially on chest. • Less contrasting plumage than others, with blotchy underparts but overall less black. • Particularly long, strong beak and legs.

Piercing abandoned albatross egg for yolk and fluid.

Natural History • Confined to Española Island, where it evolved in the absence of rodents. • Often behaving much like a rodent, scuttling along the ground beneath matted vegetation, digging between rocks, etc. • Can be highly predatory on young Territorial battles using beak and feet become quite intense. lizards, turtles and tortoises, also taking seabird eggs and chicks. Status • Very high population density, exploiting • Abundant. all habitats on the island. • Healthy population, but • Extra-large family groups, the dominant pair relying on vulnerable on single island. “helpers” to defend territories and provision nestlings. Hostile, neighboring family clans meet to defend territory boundary. Distribution limited to Española Island.

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Floreana Mockingbird Mimus trifasciatus

Endemic to Floreana Island Identification Only about 500 surviving individuals.

• Slightly smaller than Española species, but larger than other two. • Dark brown above, brown mottling on underside, white ear patches, not black as in all others.

Opuntia flowers are an important food source during the dry season.

A Common Cactus Finch aggressively drives away its competitor.

Natural History

Status

• Heavily dependent on Opuntia cacti for food and water. • Much foraging done on the ground, easily dispatching large centipedes. • Enlists grown young as helpers.

• Critically endangered and actively monitored. • Extinct on Floreana, but reintroduction plans are underway. • Remnant populations survive only on Champion and Gardner Islets, where numbers drop dramatically during dry periods.

Adult offspring are allowed to share parents’ territory by showing submissive chick behavior.

Distribution reduced to Champion and Gardner Islets off Floreana Island.

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Yellow Warbler

Setophaga petechia aureola Endemic subspecies ‡ ‡

Male bathing in tide pool.

Identification

Immature plumage.

• • • •

Status

Fledgling still dependent on feeding from parents.

Adults unmistakable due to brilliant color. • Common on most islands, but rare Vivid yellow, with greenish-olive back. on some, e.g., Pinta and Pinzón. Males have rusty cap and streaks on breast, females plain. • Apparently declining due to Juveniles pale gray and white, gradually turning to yellow, Philornis downsi vampire fly, an may be confused with Warbler Finch, but much longer tail. introduced nest parasite. • Male’s loud, clear song often responded to by female’s • ‡ ‡ Parent species widespread sharp tweets. throughout North America, migrates • Male’s rusty cap absent in mainland parent species. to northern South America.

Male showing rusty cap and streaks.

Natural History

Quick and agile Yellow Warblers are adept at catching a variety of small insects.

• A delightful little bird commonly seen from shoreline to highlands. • Feeds mostly on tiny insects fairly low to the ground. • Often seen foraging at low tide on rocky shores, beaches and mangroves. • The only land bird commonly bathing in seawater. • Builds tidy cup-shaped nest in mangroves and low bushes.

Female foraging in Scutia bush.

Widely distributed throughout the entire archipelago.

Frequently hunts tiny flies along shoreline, often among larger wildlife, such as Galápagos sea lions and Sally Lightfoot crabs.

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Galápagos Flycatcher Myiarchus magnirostris Endemic

Large-looking head, gray throat to yellow belly and double wing bars distinguish it from female Darwin’s Flycatcher. Sexes virtually indistinguishable.

Identification

Diet includes small berries, here being fed to fledgling.

• A cute, softly toned bird with pale yellow belly. • Head looks oversized, due to raisable crest. • Only possible confusion is with female Darwin’s Flycatcher, but larger head and broad bill diagnostic. • Juveniles same color as adults.

Natural History • • • • • •

A very curious little bird, often approaching people closely. Usually seen in pairs, even outside nesting season. Stalks large insects in understory, plus eats small berries. Nests in tree cavities. Its twirling notes are the first to greet the dawn. Fairly common in all habitats, with preference for arid and transitional areas.

Pairs often seen perching quietly, scanning intently for insect movement.

Preys on large moths, caterpillars and beetles.

Status • Found on all islands in variable densities, except Genovesa, Wolf and Darwin. • Population at risk from vampire fly Philornis downsi, an introduced nest parasite.

Wide distribution throughout most of the archipelago.

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Darwin’s Flycatcher Pyrocephalus nanus Endemic Male display flight, rising jerkily high in the sky and tweeting constantly, then plummeting back down to a prominent perch in the center of his territory.

Identification • The most vividly colored bird in Galápagos, male bright red with black “bandit” mask, back, upper wings and tail; formerly named Galápagos or Little Vermilion Flycatcher. • Female pale cream fading to lemon-yellow below, often with slightly streaked breast; soft brown above with faint, pale stripe above eye. • Central islands females show plain yellow front versus streaking in the western islands race. • Female may be mistaken for Galápagos Flycatcher, but daintier with less uniform markings. • Immature males similar to female, but gradually develop orange and red blotches during transitional phase.

Agile in flight and very adept at catching large insects in dense understory.

Natural History • Smaller and brighter red than its parent species, which ranges throughout drier parts of the Americas. • Perches conspicuously, then flits frequently between sub‑canopy branches to inspect understory for insects. • Territorial males fly vertically high above the forest canopy, twittering continuously, then plunge back down like a bullet. Male often delivers food (here a spider) to brooding female, who then feeds chicks. Day-old chicks camouflaged in lichen nest woven with spider webs.

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Typical coloration of adult male (left) and female (right), with immature male (center) beginning to turn red.

Recently fledged chicks, still showing tufts of down, are fed by both parents for about one month after leaving nest.

Extinct species Through genetic studies, a second, smaller species has been identified from museum specimens, Pyrocephalus dubius, restricted to San Cristóbal Island. Sadly, this is now considered extinct, or very nearly so.

Status • Populations locally extinct or in steep decline on all inhabited islands. • Reasons for decline unclear, but possibly changes in habitat due to agriculture and introduced plants. • Very sensitive to introduced avian vampire fly, Philornis downsi.

Widely distributed in appropriate habitat in the central and western archipelago.

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Galápagos Dove

Zenaida galapagoensis Endemic Identification • Large, sky-blue eye ring and bright red feet are very obvious. • A plump, subtly colored little bird and the only dove species in Galápagos, impossible to miss, scuttling busily along the ground. • Common only on islands where introduced cats are absent. During extended periods of drought, Opuntia cactus pulp provides a vital source of moisture to doves as well as a variety of other native species.

Vicious fight breaks out over water source from cactus pads.

• Natural History • A single species ranging throughout all the dry parts of the archipelago. • Feeds on dry seeds in loose ground. • Breeds after the main rainy season when grasses have seeded. • Nests mostly on the ground under rocks, but sometimes also displaces nesting mockingbirds from their tree nests. • During intense drought may eat juicy cactus pulp for moisture, or drink dew and drizzle that collects on smooth rocks (pictured at right). 34

The last seasonal rain ponds on Santiago attract doves and tortoises alike.

Normally a ground nester in secretive hollows (below), may also reuse mockingbird nests (above).

Pairs usually seen wandering around and feeding together.

Status • Scarce on islands with feral cats and rats, very common elsewhere.

Fledgling just out of the nest.

Constantly on the lookout for moisture, doves drink dewdrops off wet plants (above), or seasonal “garúa” drizzle collecting on rocks worn smooth by giant tortoises. Wide distribution throughout the entire archipelago, but now very rare on San Cristóbal and Floreana Islands.

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Dark-billed Cuckoo Coccyzus melacoryphus Native Identification • Pale brown above, peachy-cream below, with large white spots under long dark tail feathers. • Sits very still among dense vegetation, with short bursts of surreptitious flight. • Often heard but not seen, with a soft, deepening slow “laugh.” Only occasionally seen to land on the ground.

Typically perches high in dense brush.

Natural History

Status

• A native bird which is naturally very secretive and has retained its ancestral fear of humans. • Found in dense vegetation from coast to highlands. • Catches large insect prey by stalking. • Well-hidden nests very rarely seen.

• Uncommon, population fluctuates according to wet and dry years. • Widespread in woodlands and savannas of South America.

Shy and reclusive, ready to take flight at any sign of human movement.

Sparsely distributed throughout the archipelago.

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Galápagos Martin Progne modesta

Male.

Endemic Identification

Female.

Swallow-like flight with a few quick wingbeats and a long, dynamic glide.

• A small, innocuous and easily missed bird, occasionally seen hawking for insects low over ridges and cliffs, mostly inland; almost never seen perching. • Male, under certain light, glints distinctive metallic blue on the back. • Female dull gray-brown. • Quite similar to the slightly larger Purple Martin of North America, but overall duller in color and sheen. • Not to be confused with Barn Swallow, another regular North American migrant with longer, more forked tail.

Natural History • Appears to feed on a variety of flying insects, including flies, moths and sulphur butterflies. • Only one small nesting colony is known, in small sea cave roof cracks at Tagus Cove (Isabela); otherwise seems to nest in tuff cone fissures. • Almost no information exists on the life cycle of this secretive little bird, except for casual sightings. Nestlings in only known nesting site in Tagus Cove sea cave.

Rarely seen perching; male with unmistakable metallic sheen.

Status • No data exist on which to base population estimates or other baseline information.

Wide distribution everywhere except the northern archipelago.

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Feral Chicken

Gallus gallus

Introduced

Hen with flighted 10-day-old chicks.

Identification • Large, slender, reddishbrown ground bird. • Color variations exist, from black to gray. • Large, almost fan-like tail; very good flier. • Legs and beak yellow, green or black-brown. • Chicks show cryptic, quail-like color patterns.

• • • • •

Natural History

• Nests in dense ground cover. • Roosts in tree canopy, even with small chicks. Feeds on seeds, fruits, leaves, invertebrates and small vertebrates (geckos, lizards, mice). Causes considerable ground disturbance by scratching and preying on native insects and seeds. Chicks able to fly at one week or 10 days. Readily flies when frightened. In the wild, has reverted quickly to Red Jungle Fowl origins.

Hen with day-old chicks.

Distribution • Humid highlands of inhabited islands. • In wet years, ranges to coastal areas, but disappears during drought. Wild amid giant tortoises in their lush highland habitat.

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Rooster identical to original Red Jungle Fowl of Southeast Asia.

Status • Introduced; escaped from farms on all inhabited islands (descended from fighting cocks). • Rapidly expanding, especially in Santa Cruz highlands. • Range limited by availability of drinking water.

Smooth-billed Ani Crotophaga ani Introduced

Hunting large insects on the ground.

Identification • Long-tailed bird unlike any native species. • Appears jet-black in most light conditions, but subtle streaking and sheen sometimes visible. • Blunt, rounded beak, laterally flattened like a blade. • Often seen in small, sometimes noisy groups.

Pair showing affectionate behavior.

Natural History • Introduced under erroneous belief that it cleans ticks off cattle. • Nests socially in dense, isolated trees or shrubs. • Feeds mainly on large insects, in mid-canopy, low bushes, and on the ground. • A surreptitious nest predator of other small birds.

Family groups generally stay close together.

Status • Introduced species, first appeared in farming area of Santa Cruz highlands, now spread to all islands. • Considered a threat to native birds, both as nest predator and food competitor.

Breeding populations have spread and colonized all islands of the main archipelago.

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Special feature

Darwin’s Finches explained This specially expanded section will help foster a deeper understanding of the special little birds that have defined the very essence of Galápagos uniqueness. “Drab”, “confusing”, “undistinguished”, “inconspicuous”, “noisy”... all words used in various books to describe one of the most famous, intriguing and resourceful group of birds to be found anywhere in the world. Darwin’s Finches are utterly fascinating, both individually and collectively, and for the patient and inquisitive birdwatcher, they are endearingly entertaining and characterful.

Floreana

Santa Fe

Santa Cruz

Baltra/Seymour

Pinzón

Rábida

Santiago

Isabela

Fernandina

Marchena

Pinta

Small Ground Finch

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Medium Ground Finch

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Large Ground Finch

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Sharp-beaked Ground Finch

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= historic records or extinct

Island Species

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Genovesa

Española

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San Cristóbal

• = present and regularly observed º = recorded but rare

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Vampire Finch •

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Genovesa Cactus Finch •

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Medium Tree Finch

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Large Tree Finch

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Mangrove Finch Woodpecker Finch

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Vegetarian Finch

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Green Warbler Finch Gray Warbler Finch

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Española Ground Finch Small Tree Finch

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Genovesa Ground Finch Common Cactus Finch

Wolf / Darwin

Finch species distribution at a glance

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Almost 50 years ago, Dr. Michael Harris, respected ornithologist and author of the first Galápagos bird guide, famously stated, “It is only a very wise man or a fool who thinks that he is able to identify all the finches which he sees.” He also pointed out, quite rightly, that knowing which species may or may not normally be expected on each island is of great help with identification, even though rare surprises may occur. Today, his words remain as true as ever. This table should allay some of the confusion. 40

Seasonal bonanza: Various types of finches are attracted to the seasonal blooms of native Erythrina trees, using different feeding styles to reach the nectar bounty. An agile Small Tree Finch (bottom) dangles daintily to gain direct access from below, whereas a clumsier Medium Ground Finch (top) is more likely to simply tear the flowers apart. 41

Creative Commons BY-SA 2.0 Photo: Dominic Sherony.

Beginnings: Origin and evolution

Genetically, Darwin’s Finches share the same ancestor as the Dull-colored Grassquit (Tiaris obscurus), a very drab, seed-eating scrubland tanager native to northwestern South America. So a better name might be Darwin’s Tanagers, since they belong to this large family Dull-colored of New World songbirds, the Thraupidae, rather than the Fringillidae, which Grassquit: the define the world’s true finches. The accepted view is that several million years likely ancestor of Darwin’s Finches. ago a small flock of ancestral tanagers landed on the young Galápagos Islands after straying out to sea from the continental coast. Finding no competition from similar birds, they settled, multiplied and began to spread out into differing habitats. As they colonized separate islands, some populations became isolated from one another, all the while adapting their feeding habits to the local conditions. In short, they began to evolve.

Natural selection and adaptive radiation As the original finch population expanded, the pressures of natural selection began to make their mark. During dry years, on arid islands, only birds with the strongest beaks capable of cracking hard seeds survived, whereas those in the wet highlands increasingly hunted insects. When competition was intense, always the best adapted survived at the expense of those less well suited. Over time, different strains crossed and recrossed, intensifying the selection process. Some excelled at being generalists while others became specialists. Eventually they radiated into the 17 different forms we see today, each with its own song, its own habits, and its distinctly shaped beak honed to exploit various food resources.

Adult Medium (left) and Small Ground Finches show subtle beak shape differences.

All out of one mold From Darwin’s era until very recently, Darwin’s Finches were divided into 14 species, 13 in the Galápagos plus another (Pinaroloxias inornata) found only on Cocos Island near Central America. But recent genetic studies have revealed some profound Cocos differences between several island forms that were previously thought Island Finch. to be the same, raising the Galápagos tally to 17 species. Not counting a few specialist species, there are two main categories of Darwin’s Finches: the Ground Finches and the Tree Finches, the division generally corresponding to lowland seed eaters versus highland insectivores, respectively. Within each group are three species of graded beak sizes: Small, Medium and Large, with matching sets within the Ground and Tree Finches. Additionally, a few species of Ground Finches evolved in isolation on the outermost islands such as Wolf, Darwin, Genovesa and Española. Then there are those five odd and fascinating specialists: the Cactus, Vegetarian, Vampire, Mangrove and Woodpecker Finches. And finally, two versions of the most un-finch-like of them all, the Green and the Gray Warbler Finches.

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Identification tips:

Main characteristics

All Darwin’s Finches are chubby little birds with relatively short tails and wings. Their flight is weak and reactions slow compared to their mainland ancestors. This Woodpecker Finch energy-saving lifestyle reflects an environment using twig as a with low predator pressures, where outlasting tool to probe climate vagaries such as lengthy drought is lichen-encrusted branch for more advantageous than leading a grubs. high-octane life. They have strong, sturdy feet, more heavily built than Small Ground Finch landing in Scutia spines. other similar-sized birds, and are well suited for hopping around on rough lava rocks or nesting in cacti and acacias bristling with sharp spines.

Highly variable, Medium Ground Finch at left is nearly identical to Small Ground Finch (right).

Beak sizes and shapes This is the one topic where all generalities about Darwin’s Finches cease. To the contrary, every beak type speaks of countless generations of competition that perfected the optimal shape for a specific purpose. Some are best for picking the tiniest of seeds while others are designed for crushing but not for delicate food selection. A few excel at piercing and poking, some at extracting the contents of flowers and fruits; others seek hidden insects, and even seabird blood in one case. Because of the continuous honing process that natural selection imposes on each species, it seems that beak shapes are in a constant state of flux, with slight variations always being trialed for best results. Nor does each species conform strictly to its own purpose-designed food specialty; flocks of up to five or six species can often be seen operating together, targeting the same food source. Despite all such confounding factors, it is on the overall shape of beaks that one must rely for positive identification of each species, to the near exclusion of all other features — although to the trained ear, song characteristics, though variable, are also very helpful. Small Ground Finch.

Medium Ground Finch.

Large Ground Finch.

Large Tree Finch.

Medium Tree Finch.

Small Tree Finch.

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The color questions:

Above: Medium Ground Finches in breeding colors (female at far left).

Ground Finches

The plumage in all nine Ground Finches is either black (adult males) or mottled gray (females and juveniles), with all sorts of intermediates as males age and slowly change from gray to black. Some very old females may also sometimes turn quite dark. So coloration alone is of no real help in identifying species, other than narrowing it down to 9 of the 17 species!

Tree Finches The Tree Finches, including the Vegetarian, Woodpecker, Mangrove and two Warbler Finches, are all pale creamy-gray, sometimes with a tint of olive. With advancing age, males of all species except warblers acquire a black mask which gradually spreads into a hood, and rarely, down onto the body. This is particularly noticeable in Vegetarian Finches, with males occasionally turning nearly half black from the head backward.

Female (above) and male Common Cactus Finches.

Beak color

Vegetarian Finch pair. If the finches’ plumage colors are of no help in

identification, neither are the varying hues of their beaks! Beak coloration is entirely related to age and breeding condition and follows a similar gamut in all species. These may vary from bright yellow or nearly white lower mandibles in fledglings and juveniles, to adults ranging from amber (non-breeding) to all black (nesting) depending on condition and season.

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Small Tree Finches: breeding male (right) and non-breeding female (left). Irrespective of species, beak color gradients run from pale juvenile and sub-adult to amber non-breeder, gradually turning all black when nesting.

Life cycle:

Food

Broadly speaking, Ground Finches are mainly seed eaters, with differently proportioned beaks designed to crack seeds of varying sizes and hardness. Tree Finches replicate these gradients while seeking softer The Small Ground Finch is adept at foods like fruits, flowers and insects. Warbler Finches have a pincer-like beak stripping delicate seed heads. A few species have developed perfect for catching small agile insects. startling feeding strategies such as the Woodpecker, Cactus and Vampire Finches. But despite these specializations, flocks of various species feeding together are a common sight. Only when food sources are seasonally scarce do the individual Vegetarian Finch — the adaptations truly largest finch come into their own. species — eating a juicy Cordia fruit.

Seasonality

For the most part, Darwin’s Finches live by two seasons: cool/dry and hot/wet. The first is a lean time of energy saving — no singing, little territoriality, scant food and hard work searching for dormant insects and seeds. The latter season, when all the nesting takes place, is more bountiful thanks to the new flush of food triggered by two or three months of heavy rains, usually early in the year. This is even true in the highlands, which tend to be wet year-round due to cold-season mists and drizzle. Sometimes the hot rains fail completely, in which case there may be no nesting at all until the following year.

Small Tree Finch collecting moss for nesting material.

Breeding All Darwin’s Finches build spherical nests with side entrances, varying only in size and texture, reflecting the size of the owner and the available building materials by region. For example, Ground Finches near the coast mostly weave nests of dry grass, whereas highland Warbler Finches use copious amounts of moss. To guard against natural predators such as hawks, owls and snakes, nests are often placed in cacti or spiny acacias, or where these are absent, in tangles of thin branches. Up to 5 eggs are usually laid — one per day — with incubation lasting around 12 days. Chicks leave the nest at 12–14 days, but continue to be fed on the Male Common Cactus Finch feeding large, move by their parents, almost independent chick. especially the male.

A Small Ground Finch inside its dome-shaped nest woven between Opuntia cactus pads. Side entrances provide good protection; 3–5 eggs is normal.

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Profile

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Species

Range *

Habitat

Status

Noteworthy

Small Ground Finch Geospiza fuliginosa

All islands except: Genovesa, Wolf, Darwin

All habitats (arid to humid) including near-barren lava fields

Common

Most adaptable all-around generalist finch

Medium Ground Finch Geospiza fortis

All islands except: Española, Genovesa, Wolf, Darwin

All habitats with fairly dense vegetation (arid to humid)

Common

Highly variable beak sizes within same population

Large Ground Finch Geospiza magnirostris

All islands except: San Cristóbal, Española, Floreana; rare Wolf

Arid and transitional vegetation

Uncommon (extinct on Floreana)

Extra-large beaks on Genovesa and Pinta; extinct Floreana type was largest

Sharp-beaked Ground Finch Geospiza difficilis

Restricted to: Santiago, Fernandina, Pinta

Highlands only

Genovesa Ground Finch Geospiza acutirostris

Only: Genovesa

Arid vegetation and coastal scrub

Vampire Finch Geospiza septentrionalis

Only: Wolf, Darwin

Arid vegetation

Common Cactus Finch Geospiza scandens

All islands except: Española, Fernandina, Genovesa, Wolf, Darwin

Arid vegetation with healthy Opuntia forests

Common only where Opuntia cacti are abundant

Feeds on Opuntia flowers and fruit, which it defends vigorously

Española Ground Finch Geospiza conirostris

Only: Española

Arid vegetation

Common on single island

Newly identified species, with habits similar to G. magnirostris

Genovesa Cactus Finch Geospiza propinqua

Only: Genovesa

Arid vegetation, in healthy Opuntia forests

Locally common around Opuntia cacti on single island

Similar habits to G. scandens, but has much stouter bill

Rare; apparently Poorly extinct on understood San Cristóbal, species; Floreana, the only ground Santa Cruz finch dedicated to and Isabela dense understory Common on single island

New species recently split from G. difficilis

Drinks seabird Very common on blood; only two small, new species remote islands recently split from G. difficilis

Quick guide to finch characteristics Beak shape and behavior, distribution and habitat are all equally important factors to consider and cross-reference when identifying Darwin’s Finches in the field.

All photos shown at a comparative scale: Ground Finches, table at left; Tree Finches and specialists below.

*Range terms: “Only” = found on a single island (or group); “Restricted to” = small distribution ranges on disparate islands with appropriate habitat.

Profile

Species

Status

Noteworthy

Restricted to: All wellSmall San Cristóbal, vegetated Tree Finch Floreana, areas, but prefers Camarhynchus Santa Cruz, Pinzón, Santiago, Isabela, transition and parvulus Fernandina humid zones

Formerly common, but declining due to parasitic nest fly Philornis

Very active and agile; eats mainly tiny insects, aphids, flowers, buds, etc.

Medium Tree Finch Camarhynchus pauper

Only: Floreana

Seeks mature trees, mainly tall forest

Locally common; critically Feeds under bark endangered due and breaking soft to Philornis fly dead wood, often and habitat loss in high canopy in small range

Large Tree Finch Camarhynchus psittacula

Restricted to: Santa Cruz, Santiago, Isabela, Fernandina, Marchena, Pinta

All habitat with mature tall trees, but prefers humid zone

Mangrove Finch Camarhynchus heliobates

Only: Western Isabela, limited locations

Limited to mangrove forests with dry leaf litter

Woodpecker Finch Camarhynchus pallida

Range *

Habitat

Restricted to: All habitat San Cristóbal, with mature Santa Cruz, tall trees, Santiago, Isabela, but prefers Fernandina, Pinta; transition and doubtful elsewhere humid zones

Rare; apparently declining

Specialist in extracting arthropods from dead branches in canopy

Critically Intensive endangered, due ongoing rescue to introduced rat efforts, including predation and hand-raising Philornis fly; chicks plus also sea level rise predator control Uncommon and considered vulnerable

Very active; famous for tool use, practiced by some individuals only

Vegetarian Finch Platyspiza crassirostris

Restricted to: San Cristóbal, Santa Cruz, Santiago, Isabela, Fernandina, Marchena, Pinta

All habitats with lush vegetation, but prefers transition zone

Locally common (extinct on Floreana)

Eats all juicy plant matter; pairs stay together year-round

Green Warbler Finch Certhidea olivacea

Restricted to: Santa Cruz, Pinzón, Rábida, Santiago, Isabela, Fernandina

Almost exclusively restricted to lush, humid highlands

Formerly common, dwindling due to parasitic nest fly Philornis

This species recently separated from lowland form, C. fusca

Gray Warbler Finch Certhidea fusca

Restricted to: San Cristóbal, Española, Santa Fe, Genovesa, Marchena, Pinta

Mostly coastal arid vegetation, except San Cristóbal and Pinta

Locally very common (extinct on Floreana)

New species recently split from highland form, C. olivacea 47

Small Ground Finch Geospiza fuliginosa Endemic Identification • A dainty gray or black little bird, often feeding on the ground or in low bushes. • Beak shape varies little, with slightly curving lines and straight, precise tip for picking grass and other tiny seeds.

Natural History

Efficiently picking apart grass seed heads.

• Relying on very small seeds enables this species to survive where others are absent, even on seemingly barren lava fields. • Prefers to nest in low cacti or thorny bushes. • Often feeds in the intertidal zone on tiny invertebrates and fish eggs. • Provides tick-cleaning service for giant tortoises, marine and land iguanas. • Occurs in all habitats, from shore to summit.

No food source is overlooked, here plucking at a Jasminocereus cactus flower (Santa Cruz).

Status Picking small ticks from marine iguana skin.

• Populations considered stable. • Widespread on most islands.

Widely distributed throughout most of the archipelago.

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Giant tortoises often adopt an elevated stance to allow Small Ground Finches to pick ticks from hidden skin creases (Alcedo Volcano, Isabela).

Medium Ground Finch Geospiza fortis Endemic Plucking ripe Maytenus octogona fruits, then (below) cracking the hard casing to extract the 3 fleshy seeds.

Identification

(All photos this page are Santa Cruz race.)

• Intermediate between Small and Large Ground Finches. • Tremendous beak size variation in this species often defies positive identification. • Especially hard to differentiate from Large Ground Finch, with which it may hybridize; differs slightly between islands. • A common finch, usually seen on or near the ground, in fairly dense vegetation, from coast to summit.

Natural History

Two females show the highly variable beak sizes of this species. • The high variability in body and beak size appears at least in part due to Status frequent hybridization with other Ground Finches. • Populations considered stable. • A generalist which has proven adept at responding to • Widespread on most natural selection in times of food shift resulting from wet central islands. or dry periods, as highlighted in long-term studies on Daphne Islet.

Widely distributed throughout the archipelago except outermost islands. A hard Maytenus seed has to be maneuvered into just the right position to be cracked open.

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Large Ground Finch Geospiza magnirostris Endemic Identification Powerful mandibles (Santa Cruz above, Genovesa below) are capable of crushing the islands’ toughest seeds.

• Massive crushing beak bigger than all other species. • Generally unmistakable but may sometimes be confused with especially large individuals of Medium Ground Finch, particularly hybrids. • Look out for upper beak base extending well over forehead, also very wide lower mandible when viewed head-on.

A non-breeding plumage female feeding on sticky Cordia lutea fruits (Santa Cruz).

Natural History

A wide variety of foods are eaten, here on Santa Cruz feeding on an unripe Passiflora foetida (passionflower) fruit. Genovesa breeding male in full song.

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• A slow-moving bird, able to crush massive hard seeds found mostly on the ground. • Adept at cracking hard Maytenus husks or spiky Tribulus seed cases, among others. • Builds larger, shaggier-looking nests than other species. Seasonal Erythrina velutina flowers: a delicacy easily shredded to reach the nectar (Santa Cruz).

Giants among giants Special note

A Genovesa spider is quickly dispatched to make tender chick food.

When Charles Darwin visited Floreana Island in 1835, he collected a number of finches with enormous beaks. Indeed, this was an extra-large race of Large Ground Finch which is

Genovesa Island pair with black breeding bill color; the female (right) has very dark plumage, a characteristic of older birds. On Pinta Island, an evolutionary duel is running between the Opuntia cacti, with seeds developing extremely hard protective husks, and finches evolving ever-more-powerful beaks to crush them.

Genovesa juvenile splitting Bursera fruit.

now extinct, possibly due to destruction of cactus forests by fire and feral goats and donkeys. Introduced rats and cats also arrived on Floreana with early settlers, no doubt competing with, and preying on, the slow and clumsy huge-beaked finches. Today, the largest remaining versions of this species are found on Genovesa and Pinta. Unlike Floreana, these two islands remain relatively untouched and free of introduced predatory mammals, which may explain the different fate of those extra-large finches.

Status • While generally uncommon, species appears locally stable on several islands. • Floreana race extinct.

Broadly distributed throughout much of the central and northern archipelago.

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Sharp-beaked Ground Finch Geospiza difficilis Endemic Female (above and far right) is dark gray and deeply mottled; all black adult male (below).

Identification • A surprisingly plump bird, with body quite large in proportion to head and beak. • Long, pointed and nearly straight beak. • A very rarely seen finch found only at higher elevation on a few islands. • Usually observed in pairs, even when (All photos except non-breeding. lower left show Pinta race.)

Natural History • Little known, except believed to depend on land snails, which are vanishing from much of its range. • Appears to specialize in invertebrates more than any other Ground Finch. • Prefers dense forest understory habitat, feeding underneath foliage and digging in leaf litter. Flitting around in typical highland habitat, a female peeks out from lush understory (Santiago).

Status

Feeding on Succinea land snail on Pinta Island.

• Never a common species, today can reliably be found only in the highlands of Santiago and Pinta. • Has disappeared from several islands where previously recorded. 52

Distribution restricted to highland regions of just a few islands.

Genovesa Ground Finch Geospiza acutirostris Endemic to Genovesa

Identification

Foraging along beach strand when food is scarce during dry season.

• Beak small, slender, straight and very pointed. • Similar in size and behavior to Small Ground Finch, but daintier. • Found only on Genovesa, where latter is absent.

Natural History • Uses very pointed beak like tiny forceps to exploit minuscule seeds and flowers. • Feeds on the ground more than other finches, often digging for seeds in sand or dust. • May forage for invertebrate eggs at low tide during drought. • Eats pollen from Opuntia cactus flowers when available. Eating pollen from Opuntia cactus flower. Often seen actively digging for seeds in soils, scoria gravels and sands.

Fine beak is ideal for picking up and cracking the tiniest seeds.

Status • Population stable, with drops during very dry years. • Vulnerable due to single-island range.

Distribution limited to Genovesa Island.

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Vampire Finch

Geospiza septentrionalis Endemic to Wolf and Darwin Islands At first sight of blood, these feisty finches flock, fight and compete for a chance to feed.

Identification • Long, sharp beak well designed for attacking booby wing feathers, chicks and eggs. • Intermediate in size and shape between Cactus Finch and Sharpbeaked Ground Finch. • Only Ground Finch likely to be seen on these islands — some Large Ground Finch records.

Natural History • Extraordinary behavioral adaptation. • Experienced individuals, usually adult males, boldly perch on the back of nesting boobies, pry apart wing or tail feathers and pinch their base, causing bleeding (small injury not harmful to host). • Entire flocks, attracted to the sight of blood, compete for a chance to drink. • Rolls and breaks unattended seabird eggs to drink content, and kills young chicks. • Also feeds on insects and seeds, plus fish dropped by seabirds while feeding their young.

Vampires also feed on cactus and other plant seeds. The strong cutting beak serves to prey on abandoned booby chicks and to break into eggs.

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The outlying islands of Wolf (above) and Darwin (some 38 km/24 mi further NW) can be totally arid for months on end. Gangs of Vampire Finches, desperate for food and moisture, flock around nesting Nazca (above) and Red-footed Boobies (left), drinking blood by pecking at feather bases, stealing eggs and picking at fish remains dropped by seabirds while feeding their young (below).

Special note

Status

Until recently, was considered the same species as both Sharpbeaked and Genovesa Ground Finches, despite distinct beak Nazca Boobies continue to court, shape and unique behavior. oblivious to the pesky vampires.

• Abundant, but population fluctuates in dry years. • Vulnerable due to small range.

Distribution limited to the two small islands 145 km/90 mi NW of the main archipelago.

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Common Cactus Finch Geospiza scandens Endemic (All photos this page: Santa Cruz race).

Feeding on flowers provides important cross-pollination for the cactus.

Comparison of beak length and shape between Common Cactus Finch (on left) and Medium Ground Finch; hybridization occurs regularly.

Identification

Natural History

• Very long, strong, slightly curved beak unlike any other. • Always found in the general vicinity of Opuntia cacti. • Often sings from topmost cactus pad or in flight — very loud, unmelodious, staccato call. • Easiest of all Ground Finches to identify from unique bill shape.

• Although feeding on a wide variety of seeds and flowers, rarely occurs where cacti are absent. • Found only in the arid zone. • Very territorial, aggressively defending food resources against same and other species.

Male feeding two begging, almost independent fledglings.

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Song is a distinctive, powerful staccato.

Above: The Opuntia cactus connection — extracting unripe seeds from fruit and undeveloped ovules from flower (Santa Cruz).

Special note Has developed a remarkably close relationship with Opuntia cacti, piercing both flowers and fruit to feed on pollen, nectar and developing ovules, as well as unripe and ripe seeds. While damaging to the cactus, this also offers both pollination and seed-dispersal services. This relationship sometimes allows it to be the only finch species to nest successfully in dry years. Fond of nectar and pollen: feeding on Prosopis juliflora (right, Floreana) and Erythrina velutina flowers (below, Santa Cruz).

Status • Stable but population vulnerable due to high dependence on Opuntia cactus forests.

Patchy distribution only in arid-zone cactus habitat throughout most of the archipelago.

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Española Ground Finch Geospiza conirostris Endemic to Española

Identification

Tough seeds are deftly maneuvered into the optimum position for cracking open.

• A large, hefty bird with a very strong crushing beak. • Looks, behaves and sings much like Large Ground Finch, but has straighter, more pointed beak. • Usually seen feeding on the ground, actively digging for seeds between boulders. • Only found on Española. • Recent name change may lead to some confusion as it was formerly known as the Large Cactus Finch.

Seeking moisture on an arid island: above from cactus pad during drought, and drinking garúa drizzle from a smooth lava rock (below).

Natural History

• Former name (Large Cactus Finch) was something of a misnomer, as it does not have a close relationship with cacti except for moisture during drought. • Recently split as separate species from Genovesa Cactus Finch. • A very typical arid-habitat ground finch, replacing the Medium and Large Ground Finches, both absent on Española. Status • Has a predilection for, and is adept at, cracking very hard triple-spined Tribulus seeds. • Population appears stable. Viselike beak makes short work of cracking spiny Tribulus seed cases. • Vulnerable due to restricted single-island range.

Distribution limited to Española Island.

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Genovesa Cactus Finch Geospiza propinqua Endemic to Genovesa

Identification • Reminiscent of regular Common Cactus Finch, though with sturdier, more pointed beak. • Only found on Genovesa where similar species (Common Cactus Finch) is absent, so easy to identify. • Often seen on or flitting around Opuntia cacti.

Like its smaller cousin the Common Cactus Finch, this species also depends on Opuntia cactus fruits and flowers.

Natural History • Looks, behavior and song show affinity with more widespread Common Cactus Finch, more so than Española Ground Finch, from which it was recently separated as new species. • Uses strong pointed beak to exploit Opuntia cacti, plus other food sources.

Breaking into an Opuntia cactus flower before it opens.

Status • Species appears secure, despite risks due to very small single-island range.

Distribution limited to Genovesa Island. Older cactus seeds are also picked up from the ground.

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Small Tree Finch

Camarhynchus parvulus Endemic Identification

Natural History

• Pale creamy-olive, with noticeably pale eyebrows. • Older males may have black face or head. • Smallest in a trilogy of similar Tree Finches. • A dainty, acrobatic little bird foraging mostly in mid-canopy.

• Feeds on wide variety of small food items, e.g., insects, aphids, fruits, seeds, flowers, buds and shoots. • Often seen hanging upside down, unfurling curled leaves, sipping nectar or picking aphids and other tiny morsels. • Found mainly in humid highlands, but also in transition zone Small beak and well-vegetated enables precision when taking nectar coastal areas.

Dark-headed male (right) collecting nesting material (Isabela).

from Parkinsonia (at left) and Erythrina flowers (below) (both Santa Cruz).

Status Widely distributed on the larger islands of the main archipelago.

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• Common in most dense vegetation, but declining due to Philornis fly nest infestations.

Medium Tree Finch

Camarhynchus pauper Endemic to Floreana Pulling apart a longhorn beetle.

Identification • Found only in Floreana highlands. • Very difficult to distinguish from the smaller, daintier Small Tree Finch, except for distinctive song: a loud, slow staccato, shorter and lower in pitch. • Older males develop extensive black hood. • Seen mostly in tallest trees, native and farmed. Agile climber: strong feet and beak help to strip bark for finding insects.

Natural History • Entirely restricted to the highlands of Floreana. • A strong climber, spends most of its time in forest canopy. • Feeds mainly on insects, by peeling dead bark to extract burrowing larvae; also small berries.

Devouring a freshly extracted wood-boring beetle larva (above).

Status Bathing female shows beak shape and plumage color comparison with Small Ground Finch at left.

• Critically endangered. • Healthy population but limited to very small range in tall forest habitat.

Breeding male. Loud, clear song is diagnostic.

Non-breeding female.

Highly restricted distribution limited to highland forests of Floreana Island.

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Large Tree Finch Camarhynchus psittacula Endemic A parrot-like cutting beak is used to eat fruit and carve dead wood to hunt insects (Santa Cruz).

Identification • Largest of the Tree Finches, but smaller than Vegetarian Finch. • Cutting beak resembling a parrot’s. • Pale plumage; males acquire extensive black on head and body with age. Black-hooded male feeding on unripe Scalesia cordata seed heads (Isabela).

Large beak and heavy body make this species less agile and a more destructive feeder Natural History than smaller • A rare and poorly documented species. types, here pulling apart • Inhabits mainly the canopy Erythrina of tallest trees. velutina flowers • Feeds primarily on (Santa wood-boring insects Cruz).

and soft fruit.

Loud song, much slower than Small Tree Finch (Isabela).

Status • Vulnerable, possibly endangered. • Reliable only in tall trees in Santa Cruz farmland, and on Pinta and Marchena. • Population in decline, possibly due to habitat loss.

In typical lush highland canopy habitat (below), here eating fruit of Iochroma elliptica, an endemic tree (Santa Cruz). Distribution limited to forested highland habitat; doubtful or rare where pale shading.

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Mangrove Finch

Camarhynchus heliobates Endemic to Isabela

Identification

Dismantling longhorn beetle with strong, pointed beak (Isabela).

• Similar to Woodpecker Finch, but a little smaller with slightly more streaked plumage, especially breast. • Older males acquire black head. • Seen only in or near mangroves.

Natural History

Hand-rearing chicks at Charles Darwin Research Station (Santa Cruz) to boost tiny wild population.

Special note

Intensive, multi-institutional conservation aims to boost population from low ebb of around 20 breeding pairs by hand-raising chicks for release, plus ongoing rat control and nest application of organic insecticide against Philornis flies. Success recorded by captive-raised chicks now breeding in the wild.

• Entirely restricted to Captive-reared fledgling, mangrove habitat of almost western, and until recently, ready for southeastern, Isabela. release back • Hunts insects in dead to the wood, foliage and wild. leaf litter. • Said to use tool, but this is not substantiated.

Status • Critically endangered due to rat predation, Philornis fly nest parasites, limited habitat, and possibly sea level rise.

Similar appearance to Woodpecker Finch, but smaller and slightly darker (Isabela).

Highly restricted distribution limited to mangrove thickets of western Isabela Island.

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Woodpecker Finch Camarhynchus pallida Endemic

Identification • A striking, very pale Tree Finch with exceptionally long, strong beak. • Very active bird, usually working upper trunk and branches of dead or dying trees. • Often heard before seen, noisily pecking and peeling bark, dead wood, lichens and mosses in search of insects. • Strong, pointed beak and song reminiscent of Common Cactus Finch. • San Cristóbal birds differ in song, with streaked breast and black-headed males, resembling Mangrove Finch; could become new species.

Actively searching for prey among transition-zone lichens (Isabela).

Looking around for a tool after spotting insect in fissured trunk (Santa Cruz).

Natural History • Strong grasping feet and sturdy beak used to pry and break open the galleries of wood-boring insects. • May use cactus spines or twigs as tools to extract prey from deep inside galleries. • Only some individuals learn the art of tool use. • A good tool is often saved by being tucked under a foot while feeding, ready for reuse on next prey. • Found from arid to humid habitat, but more frequent in transitional vegetation. 64

Tool-using sequence (clockwise from top left): A twig or spine is broken to the right length, then used to pry and tickle prey until it can be reached and extracted, here an elk beetle grub (all Santa Cruz).

Special note Famously known as one of very few birds to use tools: either a cactus spine or fine twig shaped to size and length to pry grubs and termites out of dead wood. This tool serves same purpose as real woodpeckers’ specialized long, stiff tongues. May also “hammer” woodpecker-style, but without as much force.

Searching for insects hidden in dense epiphytic mosses (Santa Cruz).

Status • Fairly common within limited habitat. • Considered vulnerable due to limited habitat. Peeling dead twig to expose termites (Santa Cruz).

Distribution limited by habitat within the central archipelago.

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Vegetarian Finch Platyspiza crassirostris Endemic

Identification • Largest body of all Darwin’s Finches. • Exceptionally long legs and tail. • Cutting beak for eating live plant matter. • Pairs usually feed together, vocalizing regularly. • Pale greenish-beige with dark streaks makes plumage quite distinctive from other finches. • Males may develop black head and upper body with age. Masticating legume leaf (Isabela).

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Older male with black head (Isabela).

Sharp cutting beak is adept at snipping juicy, nectar-rich base of flowers, Cordia lutea (muyuyo) above, and Erythrina velutina (caco) below (both Santa Cruz).

Plucking tiny Cryptocarpus (saltbush) flowers and eating gooey Cordia lutea (muyuyo) fruit (both Santa Cruz).

Natural History • Found mostly in transitional zone, less in highlands or arid zone, except some lush coastal areas such as Puerto Ayora. • Feeds entirely on juicy plant matter, including leaves, flowers, fruits, buds, lichen and even corrosive manzanillo (poison apple) bark. • May sit quietly dozing while digesting its food. • Pairs remain close together, vocalizing frequently, regardless of season.

Eating bark of poison apple tree Hippomane mancinella (manzanillo), despite corrosive Euphorb sap (Santa Cruz).

Status • Common locally, but scarce or disappeared from some islands, e.g., Floreana. • Population apparently stable within limited habitat.

Widely distributed within limited habitat throughout much of the archipelago.

Dozing while digesting leaf matter in oversize stomach (Santa Cruz).

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Green Warbler Finch Certhidea olivacea Endemic Often sings loudly while busy foraging (Santa Cruz).

Identification

Special note

• A tiny, very busy little bird, resembling a small wren. • All over pale beige, with slightly more greenish tinge than Gray Warbler Finch. • Older males show an orange wash over face and throat. • Always flitting through dense vegetation. • Song is warbler-like, but with finch buzz.

Together, the Green and Gray Warbler Finches are the smallest of all Darwin’s Finches. They are very difficult to tell apart, except for very different ranges on eastern and western islands, with no overlap.

Natural History • Restricted to humid highlands on larger islands. • Feeds on small insects and nectar, from understory to canopy. • Highly susceptible to parasitism by vampire fly nest infestation due to small size and short lifespan. Fluffy juvenile in Miconia forest (Santa Cruz).

Status

Adult male showing orange tinge on face and throat, being chased by begging fledgling (Santiago).

• Population declining due to Philornis fly nest parasites. • Very common in highlands until quite recently. 68

Distribution limited by habitat in the highland regions of the central and western archipelago.

Gray Warbler Finch Certhidea fusca Endemic

Identification

A slender, pointed beak allows Warbler Finches to be able to feed on tiny insects on the beach (above), or to delicately sip nectar from Tribulus flowers.

• A tiny little bird, flitting about like a small wren. • All over pale beige, slightly darker and grayer on back than Green Warbler Finch. • Seen in low, dry vegetation and along shoreline. • Never found together with Green Warbler Finch. (All photos this page: Española race.)

Often forages at ground level, unlike Green Warbler Finch.

Status

• Common locally. • Population apparently stable.

Pair catching small gnats in lower intertidal area.

Natural History • Feeds on tiny insects, aphids and nectar from small flowers. • Forages almost entirely at ground level or in low vegetation, also in intertidal zone.

Distribution limited to eastern and outlying islands.

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Brown Pelican (Pelecanus occidentalis urinator): Found along all coastlines, except Darwin and Wolf Islands, these common seabirds are ubiquitous, especially in sheltered shallows and mangrove inlets, plunging from on high to entrap small fry in their expandable pouch. They are also opportunistic feeders, attracted to multi-species feeding frenzies, sea lions dismembering large prey or fishermen discarding offal.

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Part 2

Seabirds

Part 2 Seabirds opening spread

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Endemic or Not? Endemism on the high seas — what does it mean?

Galápagos Petrel Once named the Darkrumped Petrel, and thought to be a native population of the Hawaiian Petrel; modern taxonomy has classified this large gadfly petrel as a fully endemic Galápagos species.

Ecologically speaking, when a species is “endemic” to a given location, the meaning is very clear: it is found there, and nowhere else. This applies especially to islands, because they are small, finite, and isolated. Easy to define. But when it comes to seabirds, how should the word be applied? Is a species endemic to the island it breeds on, or to the oceanic area it feeds in? Usually the former applies (as with the Galápagos Petrel), but this could easily be contested. And what happens when 99% of a species’ population breeds on one island (e.g., the Waved Albatross), but a few stragglers show up somewhere else? Or (like the Brown Pelican) when the local type looks different, is fully resident, but is regarded as a subspecies only, not a separate species? Where should one draw the line? For the purpose of this guidebook, I have chosen to label as “Endemic” those species, as well as visibly distinct subspecies, whose breeding ranges are clearly centered on Galápagos, even though some limited nesting might occur in other islands or regions. As for the previous section, a qualifying double dagger sign ‡ ‡ (e.g., Endemic ‡ ‡) refers to further explanations and details in the individual species description.

The term “Native” is used when a bird nests in Galápagos but the archipelago is only part of that species’ broader breeding range.

Examples of seabirds found only in Galápagos: • Galápagos Shearwater (left) and Lava Gull (right). Examples of two endemic seabirds who have forsaken all ancestral ties to make Galápagos seas and coastlines their exclusive home. • Flightless Cormorant and Galápagos Penguin. These two species represent the epitome of island isolation, being not only adapted to a unique archipelago, but further limited to specific areas fed by the nutrient-rich upwelling of the Cromwell Current. 72

Waved Albatross (Phoebastria irrorata) Rarely seen in Galápagos outside of the breeding season; its main feeding grounds are located in the cold upwellings of the Humboldt Current off the coasts of Perú and Ecuador.

Examples of Galápagos seabirds shared with other regions: • Swallow-tailed Gull (left). Small numbers also nest on Malpelo Island off Colombia. Non-breeders range south off the Peruvian coast. • Brown Pelican (right). Ranges up both tropical coasts of the Americas and Caribbean, but divided into 5 distinctively colored subspecies, one of which is restricted to Galápagos. • Waved Albatross (backdrop). A small colony nests on Isla de la Plata near the Ecuadorian coast. 73

Galápagos Penguin Spheniscus mendiculus Endemic Identification

• Unmistakable, the only penguin found near the equator. • Boldly black and white, seen from behind blends completely with lava shore. • Single irregular black-and-white stripe borders breast, plus a fine white band curves around cheeks and under chin. • Random black flecks on white chest specific to each individual. • Bare pinkish-orange skin near base of beak and brownish eye Typical adult markings with blackJuveniles lack adults’ distinctive markings. and-white stripes on chest and throat. are the only color markings. Natural History • Juveniles dark slate-gray, indistinctly fading to white front. • Found where nutrient-rich, cold • Somewhat duck-like appearance when bobbing at surface. upwellings are strongest. • Voice is melancholy rhythmical braying, or single-note • Feeds mostly on small schooling contact call at sea. fish in near-shore shallows, either alone or in small groups. Distribution • May participate in feeding • Stronghold in cold frenzies with diving pelicans. Cromwell Current • Lays two white eggs in dark around Fernandina rock cavities; incubation 38–42 and western days; fledging around 60 days. Isabela south to Puerto Villamil. • Normally nests in cold season May– December; may raise 2–3 clutches • Tiny permanent Penguins spend many hours every when food conditions optimum. colonies on Floreana day in the water, preening (above) and and eastern Santiago. • Longevity: approx. 14–16 years. fishing, often in small groups (below).

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Diminutive size is most noticeable when seen alongside other species such as Galápagos sea lions.

Special note

Courtship cuddle prior to mating. Typical nest located in rocky cleft, sparsely lined with mangrove and other plant debris.

This world’s second smallest penguin is related to three subtropical penguins: Humboldt (closest ancestor), Magellanic and African. It is very susceptible to El Niño conditions, when prey species disperse, causing breeding failure and starvation.

Courtship involves loud braying and jerky head movements.

Status • Endangered. • Current population estimated at 4,000 individuals, less than half pre1980s numbers. • Climate change, alien pathogens, illegal gill netting and even volcanic eruptions have all been identified as potential threats to long-term species survival. Groups come ashore at dusk to roost on lava rocks.

Juvenile perching on large marine iguana.

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Waved Albatross Phoebastria irrorata Endemic ‡ ‡ Banking into the wind, dynamic soaring uses wind power to save energy.

Identification

• Unmistakable, even at sea, by its size and extremely slender wings. • A mid-sized albatross, larger than Hawaiian types, but much smaller than the predominantly white species of the southern latitudes. • White head, grayish-brown body and exceptionally long, richly yellow beak. • Females slightly smaller, with slimmer beak, than otherwise identical males. • Juveniles same plumage as adults.

Natural History

Unique tufted “eyebrows” and bare black eye rings evoke a quizzical look.

• Nesting cycle from late April to mid-January, when all birds leave land. • Doesn’t build nest; large, single white egg laid on bare ground, often moved some distance by shuffling, may cause egg loss. • Incubation 65 days; chicks hatch July–August; fledging December–January. • Courtship seen throughout breeding season, by young or unmated birds, or pairs that failed to hatch a chick. • Longevity: approx. 40 years. Fine wavy lines on body feathers (left) are source of common name.

Below: Prolonged and intense group courtship rituals may suddenly turn into brief fights between male contenders.

A complete courtship session involves strictly choreographed sequences of fencing, bill-clapping, gaping and sky-pointing.

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Able to soar in very little wind and low over water, unlike larger cousins in higher latitudes.

Special note The only truly tropical albatross of 22 world species. Regularly commutes to feed in Humboldt Current upwelling off the coasts of Perú and southern Ecuador. Rarely seen in Galápagos outside of breeding season. Española Island is its only breeding stronghold, sprinkled in loose colonies along southern plateau. Up to approximately 70 pairs also nest on Isla de la Plata near the Ecuadorian coast, but are rarely successful.

Distribution •

Nesting colony in boulder-strewn clearing.

‡ ‡ Primary nesting ground Embedded fishhook on Española, plus a small from longline fishery. colony on Isla de la Plata, Ecuador. • ‡ ‡ Feeding range in Humboldt Current, from southern Ecuador to Perú, sometimes in nearshore waters. • Limited feeding grounds in SW Mosquito plagues are common Galápagos waters. after very heavy rains.

Status • Critically endangered. • Estimated population 31,000–36,000 individuals. • Although safe in Galápagos waters, adult mortality from fishhooks (esp. longlines) near mainland coast is principal cause for decline. • El Niño conditions promoting severe mosquito outbreaks lead to nest abandonment. Chick is fed on regurgitated stomach oil.

Incubation shift between partners.

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Galápagos Petrel Pterodroma phaeopygia Endemic Identification

Characteristic dynamic soaring flight features regular rise and fall in windy conditions.

• A classic “gadfly petrel” with long, slender wings and deep, powerful wingbeats when not dynamic soaring, much larger than Galápagos Shearwater. • Dark gray and black above, with mostly From above white underparts, throat and forehead. appears all • Seen near shore only when approaching dark except for nesting islands at dusk, sometimes calling. noticeable white forehead. • Courtship call loud “kik-kik-kik–hoooo.” • Often can be heard at night overflying inhabited regions en route to nesting grounds.

Natural History

Shuffles along ground to reach nest burrows, scrambling onto vegetation for takeoff.

• Apparently feeds mainly on squid taken by surface-seizing or dipping on the wing. • Nests in burrows located in wettest parts of highlands. • Strictly nocturnal at nesting grounds.

Distribution

Status

• Nests in highlands of Santiago, Santa Cruz, Floreana, small numbers on Isabela and San Cristóbal. • Can be seen offshore during cold season, mostly between Santiago and Isabela. • Pelagic feeding range south to offshore Perú / Chile.

• Critically endangered. • Severe population decline by predation from feral pigs, dogs, cats, rats. • Extermination of pigs and ongoing rat control is safeguarding some colonies on Santa Cruz, Santiago and Floreana.

Nest burrows hidden in dense understory; single chick awaits feeding by far-ranging parents.

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Strong and rapid flight, with stiff wingbeats, usually skimming close to the surface of the sea.

Identification

Galápagos Shearwater Puffinus subalaris Endemic Natural History

• Most prevalent yet perhaps least noticed of all Galápagos seabirds. • Dark brownish-black above with white underparts. • Commonly seen skimming sea surface on rapid wingbeats. • Western population with dark underwings may prove distinct.

• Formerly regarded same as Audubon Shearwater, but now a separate species. • Feeds on tiny fish larvae by “flying” underwater. • Often gathers in large, noisy flocks feeding with schooling tuna and other predatory fish. • Nests deep in cliff-face fissures. Pair at typical cavity nest entrance. • Diurnal at nesting sites, unusual for petrels.

Distribution

Status • Very common. • No census exists, but likely the most common seabird in Galápagos.

Usually flies low, straight course over water.

• Omnipresent throughout Galápagos waters. • Nests in all sea cliffs. Below: Often feeds in large flocks, scurrying along surface and “flying” underwater in pursuit of tiny fish.

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White-vented Storm Petrel Oceanites gracilis galapagoensis Endemic subspecies ‡ ‡

Above and left: broad, rounded wings, widely fanning tail, even-width white rump band and legs longer than tail are all diagnostic features.

Indistinct white underparts give this species its common name.

Identification Feeding on tiny fish-oil globules in the wake of marine predators, while “walking” on water.

• A tiny bird, all dark brownish-black, with clearly visible white rump and diffuse pale underbelly. • Rounded wings give it a butterfly-like fluttering flight. • In flight, long legs and feet protrude beyond tail. • Patters along surface on spindly, dangling legs for prolonged periods while feeding. • Conspicuously feeds much closer inshore than other storm petrels.

Characteristic bouncy flight low over sea surface.

Natural History

Flocks are very rarely seen quietly resting on water.

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• Feeds on tiny surface debris, plankton and especially globules of oil around large predator kills; also galley wastes around ships. • Present year-round, yet nesting sites have so far defied detection. • According to recent banding studies, individuals spend long periods in small areas, unusual for storm petrels.

Prominent tubular nostrils enable good scent detection. Left and below: Long legs dangle during feeding flight, frequently dabbling and stirring the surface.

Special note The smallest of all seabirds, weighing 14–24 g (0.5–0.8 oz), with 25 cm (10 in) wingspan, this endemic subspecies is likely to emerge as a new species.

Distribution • Seen very close inshore around south-central and western islands, but nesting grounds are unknown. • ‡ ‡ A separate subspecies, called Elliot’s Storm Petrel, Oceanodroma gracilis gracilis, inhabits coastal waters of Perú and Chile. Only storm petrel habitually seen near shore in bays and anchorages.

Opportunists for any food sources, seen here following orcas feeding on sea turtles.

Status • Common year-round. • Nothing is known about this species’ population numbers or life cycle.

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Wedge-rumped Storm Petrel

Oceanodroma tethys tethys Endemic subspecies ‡ ‡ Identification

Size, rump marking and wing shape distinguish top right bird from smaller White-vented storm petrels.

Natural History • Uniquely among storm petrels, is diurnal on nesting grounds, with large flocks swarming above lava fields and ducking into small lava cavities, May to November. • Feeds on small planktonic organisms and detritus snatched from sea surface. • Year-round resident. • Regular prey for day-hunting Short-eared Owls. • Also known as Galápagos Storm Petrel.

Diagnostic traits: triangular white rump; pointed wings; pale wing coverts; and legs that do not extend beyond tail.

• Classic black-and-white storm petrel coloration can be distinguished with certainty by large triangular (wedge-shaped) white rump patch. • Second most frequently seen storm petrel, but generally less coastal than White-vented. • Also larger, with slender, pointed wings and stronger, substantially more zig-zagging flight. • Dabbles feet on water only briefly compared to White-vented.

Distribution • Three nesting colonies in Galápagos: Genovesa southeast cliffs, Roca Redonda (Isabela), Islote Pitt (San Cristóbal). • ‡ ‡ Another subspecies, O. t. kelsalli, nests on Peruvian islands. • Species ranges widely offshore, from México to Chile.

Status • Common. • Little known about life cycle. When fanned, tail is rounded, with prominently visible white triangle. Only occasionally dabbles feet.

Below: Large diurnal colony, with thousands nesting in lava fissures on Genovesa’s southeast coast.

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Legs visibly shorter than tail; white on rump less extensive than Wedgerumped, does not extend over black tail feathers.

Band-rumped Storm Petrel Oceanodroma castro Native

Identification

Tail fan is straight, with narrow band of white feathers.

• Very similar in size and appearance to Wedge-rumped, but white markings limited to even-width, crescent-shaped band rather than triangle. • Heavier set than others, especially head and neck. • Short legs do not protrude from tail in flight. • Seldom seen, even at sea. • Also known as Madeiran Storm Petrel.

Natural History • A typical storm petrel, scouring the high seas for planktonic tidbits and fish debris, snatched from surface. • Nests in many small colonies along cliff edges and small islets, arriving Landing near nest under complete darkness, Plazas Island. and departing during darkest hours. • Often the only signs of nesting activities are owl predation remains. Incubating single egg in small cliff-face crevice, Plazas Island.

Slender body, with strong neck and head.

Distribution • Nests thinly dispersed in cliffs throughout archipelago. • Widespread throughout tropical Pacific and eastern Atlantic Oceans.

Remains of carcass from Short-eared Owl predation.

Status • Common and wide-ranging. Sturdy bill with large tubular nostril; a defining characteristic of the Procellariformes — the large taxonomic family of all petrels and albatrosses.

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Blue-footed Booby Sula nebouxii

Juvenile plumage drab brown and white; acquires blue feet in second year.

Native

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6

1

Identification

This seven-image, complete dive sequence reveals the fastaction, arrow-like precision of booby fishing techniques.

• Large streamlined body, spear-like beak, long tail, and dazzling blue feet impossible to mistake. • Distinctive from other boobies, even in flight, by white underside, dark wings and mottled back. • Juveniles similar to adults, but light brown head and neck extending to chest and fading to white; gray legs and feet. • The only booby commonly seen diving very near shore. • Voice distinctive: females honk, males whistle.

2

(1) aligning on selected targets; (2) powered, fast downward flight; (3) stretching wings back behind body;

Natural History

5

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• Feeds by plunge diving, kamikaze-style, on herring, anchovy, sardines and other fish, sometimes in remarkably shallow waters. • Clever, second form of diving involves skimming surface, ducking under at full speed to catch surface needlefish. • Forms noisy colonies whenever food supply plentiful, usually in the cooler months. • Lays two greenish-white eggs, sometimes three or four. • Eggs hatch a couple days apart, so older chicks have advantage over siblings; smallest starve during low food supply. • Juveniles return to nest site to be fed by parents for several weeks after fledging. • Incubation time: 41–45 days; fledging: 108 days; juveniles independent from parents: ±130 days.

Clockwise from top:

(4) smoothly breaking sea surface at up to 100 km/h (60 mph); (5) arcing bubble trail of dive trajectory; (6) swimming using wings and feet and catching individual prey; fish can be swallowed underwater, at surface, or in flight;

3

(7) emerging with herring ready to swallow whole. 4

Male landing “salute” to impress female.

Though no nest is built, pairs use a symbolic twig during courtship.

Lacking a brood patch, large webs are used to incubate up to 3 eggs.

Distribution

Special note

• Feeds throughout Galápagos, mostly close to shore. • Nests on most islands close to food supply (some colonies only transitory), except in north. • Also found along the Pacific coasts of México, Ecuador and Perú.

Sky-pointing, with a drawnout, descending whistle, is the apex of male courtship.

Status

Females are 25% larger than males, with larger-looking pupils due to black iris markings. Although found elsewhere, Galápagos is a stronghold for the species. A favorite Galápagos seabird thanks to its endearing courtship dance, this is nonetheless an embattled species. Changes in food supply, perhaps driven by climate change, have caused numbers to plummet in the last two decades.

• Commonly seen yet decreasing in numbers. • Species closely monitored by researchers.

Courtship dance centers around blue feet, with slow and exaggerated high-stepping.

Below left to right: first three monthly stages of chick development: 1) up to one-month-old chicks sheltered by parent while growing first down; 2) fluffy chicks well protected by thick down coat; 3) molting into juvenile plumage.

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Red-footed Booby Sula sula

Identification

Native

• As with its blue-footed relative, red feet are diagnostic, but not always visible. • Powder-blue beak and face, trimmed with pink, are unique features. • In flight, more slender and acrobatic than other boobies, with sharply pointed wings and long tail. • Usually pale brown, but some individuals white. • Juveniles completely brown with black beak, gray feet. • Voice: a loud and piercing “aaaaark”; low staccato rattling during courtship. • Only Galápagos booby to be seen perching in trees. Single egg laid, incubated for 41–45 days. Both parents tend chick until fledging at about 1 year old.

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Color-dimorphic pair: brown versus white plumages share identical facial markings.

Natural History • Oceanic feeder nesting only on outer islands fringing archipelago. • Unlike other two boobies (both ground nesters), builds stick platform in coastal shrubbery. • Single white egg, 41–45 days incubation; about 1 year to independence, a reflection of long-distance feeding trips. • Often harassed by pirating frigates stealing food or nesting material in flight.

Distribution • In Galápagos, nests only on Punta Pitt (San Cristóbal), Gardner Islet (Floreana), Genovesa, Darwin and Wolf. • Widespread in all tropical seas, nesting on remote islands in Atlantic, Pacific and Indian Oceans. • A farranging, pelagic seabird rarely seen near shore except on nesting islands.

Adult white morph is less common in Galápagos.

Adult brown morph.

Special note A worldwide tropical species in warm oceans. Feeds mainly on flying fish in open seas: adept at skimming fast and low over the surface, scaring the fish into flight, then catching them on the wing. About 95% of Galápagos birds are creamy brown, 5% white with lemon tinge on head and black primary feathers; elsewhere in range this proportion is reversed. Some intermediate colorations occur. Nesting material is carefully selected by male (above), then presented to female at nest site.

Juvenile in flight showing long, slender wings.

Status • Widespread and apparently stable. • Genovesa has world’s largest nesting colony, estimated 140,000 pairs. Fledglings explore freely while still dependent on their parents for food.

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Nazca Booby Sula granti Native

Adult plumage is identical in males and females.

Identification • Large, dazzling all-white seabird with black wing and tail feathers. Sky-pointing display • Bright, peachy-orange beak more slender and graceful is more subdued than other boobies. than similar Masked Booby. • Feet vary in color from dark gray to slateblue, even tending toward khaki green. • Juveniles mainly white underparts, mottled brown head and neck; feet and beak dark gray. Can be confused with Brown Booby (Sula leucogaster, rarely seen in Galápagos) but lacks sharp brownwhite border on breast. • Sexes look alike, though female 15% heavier, and voices very distinctive: males whistle; females very loud honk. Mate returning from fishing prompts loud pair greeting calls.

Natural History • Very powerful plunge diver, mainly in deep offshore waters. • Flocks often feed in association with dolphins, tuna and other predators. • Variable-size nesting colonies on bouldery plateaus or cliff edges. • Lays two white eggs (very rarely 3 or 4) but first-hatched chick almost invariably kills younger sibling(s) soon after they hatch. • Incubation lasts 44 days; fledging at 4 months; parental feeding extends another month. • Males more numerous than females, and fight viciously for mates. • Aggressive male tendencies sometimes lead to attacks on unrelated large chicks. • High mortality of far-ranging juveniles before adulthood. Good binocular vision is essential for accurate plunge diving from up to 50 m (160 ft) high. Below: Inquisitive fledgling peering below sea surface.

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Distribution • Seen throughout Galápagos, but nests mainly on outer islands with largest colonies in north at Darwin, Wolf, Genovesa, and in south at Española and Gardner Islet (Floreana). • Elsewhere: largest colony Malpelo Island (Colombia); smaller numbers on Isla de la Plata (Ecuador), Revillagigedos (México) and Clipperton Atoll.

Special note

Immature plumage. Two-month-old chick begs to be fed.

Males engage in vicious fights over prime nesting sites.

Separated as different species (2002) from wide-ranging Masked Booby (Sula dactylatra), which doesn’t occur in Galápagos. Species division is demonstrated on Clipperton Atoll, where both nest side by side.

Status • Galápagos population — almost half the world total — appears stable, though decline in sardine prey has reduced breeding success.

Attentive parents will regurgitate increasingly large fish as chick grows. Obligate siblicide: First-laid egg hatches 4 days before second, with older chick always driving its new sibling from the nest.

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Great Frigatebird Fregata minor Native Green feather sheen on back is diagnostic for males.

Identification

2.3 m (7.5 ft) wingspan is shorter than Magnificent Frigate.

• Slender, high-flying silhouettes make frigatebirds unmistakable, but the two Galápagos species hard to tell apart, especially at a distance. • Smaller than Magnificent Frigatebird. • Beak slighter and more curved. • Male courtship balloon heart-shaped when fully inflated.

• Key distinguishing features: — Male: all black with shiny metallic green sheen to back feathers in some lights; — Female: white breast extends up throat to lower beak; pink eye rings; — Juvenile white head and breast with variable rusty wash. • Rarely seen at sea except near nesting islands. Fully inflated pouch is heart-shaped.

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Males are able to fly with fully inflated pouch, yet it can be deflated/inflated in about 30 minutes.

Male carrying nesting material.

Natural History • Catches mainly flying fish in flight: either when pursued by other fish below or swooping low to flush them up. • Adept at stealing food, and nesting material, from other seabirds. • Forages over vast open ocean range without landing. • Males inflate throat pouch for courtship display, calling and shaking their shimmering wings at passing females. • Lays one white egg only; 55 days incubation; fledging around 5 months, but mother continues to feed juvenile while it learns to fish for up to 18 months. • May visit inland freshwater pools to drink.

Below: When courtship changes to pair-bonding, the male’s pouch shrivels; he soon dedicates himself to gathering nest-building supplies. Note female’s pink eye ring.

Juvenile plumage: rusty tinge to white head/breast.

Distribution • Nests in shrubby vegetation on outlying islands: Darwin, Wolf, Genovesa, San Cristóbal, Española, Gardner Islet (Floreana). • Ranges widely in all tropical seas, nesting on distantly dispersed oceanic islands.

Special note Mid-air piracy: male deftly snatches a prime nesting twig from an irate Red-footed Booby.

Female drinking from freshwater pool.

May perform most life functions in flight — feeding, preening, bathing, sleeping — except reproduction, for which it needs to come to land. Plumage not waterproof, so cannot submerge or sit on water, or it becomes waterlogged and drowns. Covers thousands of miles of ocean, spending minimal energy by circling inside thermal updraft clouds at sea, rising effortlessly to 2,500 m (8,000 ft) or so, then gliding to other rising cloud formations. Recent studies also reveal it can sleep in flight for several minutes without losing control.

Typical nesting colony with competing males displaying in low saltbush, Genovesa.

Female with 2-month-old chick.

Status • Apparently stable, although not known if interchange exists between other parts of world.

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Magnificent Frigatebird Fregata magnificens Native

Juvenile with white head and breast but no rusty color.

Purple feather sheen on back is diagnostic for males.

Identification

Natural History • Slender, high-flying silhouettes make frigatebirds unmistakable, • Primarily a coastal scavenger, keeps extremely but two Galápagos species hard to tell apart. sharp eye from high soaring position. • 2.4 m (8 ft) wingspan, 1.1–1.6 kg (2.5–3.5 lb), • Drops in seconds for sea lion, orca or tuna kill, or larger than Great Frigatebird. fishing boat offal discards. • Beak heavier and less curved. • May bathe in fresh or brackish pools by ducking head and body, keeping wings clear. • Male courtship balloon is oblong, extending from beak to below chest. • Males inflate huge throat • Key distinguishing features: pouch for — Male: all black with purplish courtship metallic sheen on back in display, some lights; shaking — Female: white breast shimmering demarcated by wings at V-shaped black throat; passing bluish-gray eye rings; females. — Juvenile: completely • Lays single white head and chest. white egg. • Regularly seen Female feeding 2-month-old chick. • Incubation soaring high above shorelines 40–50 days, fledging around 5 months, but and between juvenile fed by female for around 6 months longer. Male courtship balloon narrower, islands. Female’s black head merges into bold black V-shape on white chest. more oblong than Great Frigatebird.

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Ever vigilant, a soaring flock appears to defy gravity.

Distribution • Omnipresent in coastal and inter-island waters. • Sparse nesting colonies in mangroves or saltbush: Seymour, San Cristóbal and southwest Isabela, also among Great Frigate colonies on Wolf, Genovesa, Tortuga, Gardner Islet (Floreana). • Species ranges west and east coasts of Americas, and Caribbean to Cape Verde off west Africa.

Intense jostling for food while keeping wings clear of water.

Special note Largest of all 5 species of frigates, with extraordinarily acrobatic flight when competing with each other or stealing from other seabirds, even capable of hovering and flying backward. Deft aerial acrobatics include stealing food (bottom), high-speed swooping descents and mid-air fighting (above left and left) and even bathing on the wing (above).

Three-month-old chick flexes its growing wings.

Their aerial prowess inspired the 18th-century seafarers’ moniker of “man-o-war bird,” with their scientific name being derived from the French frégate — a fast warship. Preying on live Galápagos Shearwater in flight.

Status • Stable in Galápagos despite limited suitable nesting sites.

Pirating techniques include skilfully snatching regurgitated food from boobies as it passes from parent bill to chick. 93

Flightless Cormorant World’s largest cormorant stands about 60 cm (2 ft), weighs up to 4.5 kg (10 lb), with ragged wings but powerful legs.

Phalacrocorax harrisi Endemic

Natural History

Identification • A massive bird, clearly flightless even when tiny wings not visible. • Plumage dark brown, pale buff throat and chest; bright blue eyes. • Huge, black webbed feet. • Juveniles almost solid black, dark gray eyes. • Body totally submerged when swimming, long snaky neck held upright. • Male weight 4.5 kg (10 lb), 37% heavier than female, otherwise sexes identical. Feeds on a wide variety of bottomdwelling fish and octopus; here eating a trumpetfish almost as long as its body.

• Deep diver, recorded to over 70 m (240 ft), hunts bottom fish in boulder or algae fields Typical adult resting by agile systematic searching pose on lava shorelines. of cracks and holes, with short, high-speed chases. • Ragged wings extended to dry after each fishing trip. • Normally lays 2–3 white eggs in seaweed nest on rocks just above high tide. • Incubation 35 days; fledging Vivid turquoise eye in adults. two months, two months additional care from father. • Highly unusual breeding system termed “sequential polyandry,” whereby female usually abandons half-grown chicks for father to raise, and starts Massive new nest with another male. webbed feet. • Longevity: approx. 17 years.

Dives can be deep and last several minutes; long snaking neck and strong bill used to hunt out hidden rock-dwelling fish.

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Distribution • Extremely small range at the heart of Cromwell Current upwellings, western Isabela from Cabo Marshall to Caleta Iguana, and all around Fernandina.

Diligent males regularly bring seaweed offerings to females sitting on the nest.

Special note Largest of world’s 35 cormorant species, uses powerful feet for underwater propulsion, not wings. Long stiff tail as rudder provides high maneuverability. Hair-like feathers easily soak up water, with minimal trapped air reducing buoyancy for ease of deep diving. Resulting poor insulation limits feeding time, so needs drying/warming periods in between. Certain individuals decorate their nests with quirky items like starfish, sea Lays up to 5 eggs, but usually urchins, even mummified iguana carcasses. only one or two chicks survive.

“Water dance” courtship involves a ritual of circling and vocalizing with bent necks.

Status

Individual personalities are reflected in a surprising selection of nesting materials used; aside from the normal seaweed (top right), starfish (above), urchins (left middle) and even marine iguana carcasses (top left) can all be proudly featured.

• Species highly vulnerable due to very limited range and small population, estimated around 3,000 individuals. • Overall stable, though numbers fluctuate between La Niña (up) and El Niño (down) events.

Typical cone-shaped seaweed nest among marine iguana colony.

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Red-billed Tropicbird Phaethon aethereus Native

Identification Natural History

Evolved for a life at sea, short legs make it unable to walk; requires landing at, or very close to, nest cavity before shuffling into nest.

• Glossy white with black speckling on back; black primaries and eye bands on sides of head. • Bright red beak, black and yellow webbed feet. • Long, white, double streamer feathers trail stiffly from tail. • Juveniles same color as adults, but pale yellow beak. • Flies fast and high over ocean on stiff, rapid wingbeats.

• Pelagic plunge diver, feeds especially on small fish and squid, sometimes taking flying fish in flight. • Often repeatedly harassed by pirating frigatebirds. Violent, noisy fights regularly break out over competition for prime nesting holes. • Nests in loose colonies, using holes and fissures in sea-facing cliffs. • Group courtship, circling near nesting cliffs, with ear-piercing calls and V-shaped flight postures. • Lays one egg, finely mottled reddish-brown; incubation 42–44 days; fledging 3 months. Nesting among trunks of Opuntia cacti on Champion Islet, Floreana.

Developing chicks in sheltered nest cavities.

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Group courting display flights, mostly in early afternoon, are always punctuated with loud screams.

Distribution

• Nests in most sea cliffs and steep islets in Galápagos, particularly central and eastern. • Range: throughout tropical eastern Pacific, Atlantic and western Indian Oceans.

Status • Generally stable, possibly increasing in Galápagos. Nesting beneath Nazca Booby colony.

Special note

Braking on final approach toward nest cavity.

Truly oceanic bird, approaches land only for breeding. Travels widely, with some Galápagos-banded birds recorded near coasts of Central and South America. Investigating potential nest hole.

Upended for its fish catch by pirating frigate.

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Brown Pelican

Pelecanus occidentalis urinator Endemic subspecies ‡ ‡ Identification

Banking into a plunge dive: can vary from a low-level flop to a full-on 20 m (65 ft) high plunge.

• The only pelican in Galápagos, impossible to confuse with other seabirds. • Adults streaky gray, cinnamon-brown neck, white head, sexes identical. • Unlike other subspecies, at onset of breeding, beak turns bright pinkish-orange, pouch blackish, head acquires lemon-yellow wash and small crest; neck briefly molts pure white then reverts to normal brown. • Juveniles grayish-brown above, white below.

Natural History

• Spectacular plunge diver targets schooling fish in shallow, murky waters. • Also an opportunistic scavenger, follows human fishing activities. • Small nesting colonies with large nests in coastal saltbush or white mangroves. • Normally lays 3 white eggs: incubation 28–30 days; fledging 75 days, successfully raising all chicks only when food supply plentiful.

Status

Juvenile plumage.

• Common; apparently increasing in Galápagos. 2–3 eggs laid in grass-lined platform nest. Chicks hatch naked before growing white down.

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Rapid upward flicking of head to stretch flexible skin of pouch.

Distribution • Found around central and western islands, especially shoaling coastlines and mangrove inlets. • ‡ ‡ Four other subspecies inhabit the west and east coasts of North and South America, respectively, plus the Caribbean. Chicks receiving meal of regurgitated fish; size differences reflect staggered hatching.

Plunge diving sequence: as prey is sighted the dive is like a guided free fall, finally extending neck and beak and crashing into the surface to engulf prey inside the pouch.

Special note Expandable pouch and highly flexible lower mandibles engulf and strain out schooling prey, from tiny fish larvae to large mullet. This skill not easily honed by juveniles, many of whom starve during the learning period. Left: Early breeding colors begin with white neck; turns brown at egg-laying time. Below: Courtship consists of head waving with outstretched wings and pouch (note contrasting stages of neck molt).

Plunge diving seen from below: holding up to 8 liters (2 gal) of water, the pouch acts as a huge dip-net trapping fish inside as water is slowly drained away.

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Long wings provide buoyant flight and agile maneuverability.

Swallow-tailed Gull

Creagrus furcatus Endemic ‡ ‡

Adult in flight; sexes identical.

Identification • Extremely elegant, predominantly white gull, with light gray back, black head and wing tips, and bright pink legs. • Huge bulging eyes thickly rimmed with bright orange eye rings. • Beak black with noticeable white tip and white-feathered base. • Non-breeders’ head white with black smudge around eyes, rarely seen in Galápagos. • Juveniles mostly white with mottled brown back, black around eyes, pinkish-gray feet.

Courtship involves mutual preening (above), chick-like begging by female (below), often followed by ritualized feeding by male.

Non-breeding plumage, rarely seen in Galápagos.

Natural History • Flies far out to sea at dusk, hunting mainly squid at night. • Forms large, loose colonies nesting mostly on cliff ledges, also vegetated island plateaus, and occasionally on beach (Genovesa). • Nests on ground, on ledges or on flat lava boulders. • Nests lined with small stones, shells or coral pebbles. • Lays single pale greenish egg, Young chicks wander freely heavily blotched from the nest site, here stretching growing wings. with brown. • Incubation 33–35 days; fledging at 2 months with parental feeding for a further 2 months. • Small chicks vulnerable to predation by owls, hawks, frigatebirds, even crabs. Juvenile in submissive begging posture.

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Ghostly white shapes of hunting Swallow-tailed Gulls can often be seen when sailing between islands under a full moon, hovering occasionally, then rapidly dipping to snatch squid near the surface.

Distribution • Present on many windy cliff edges throughout archipelago, with largest numbers on Española and Genovesa. • ‡ ‡ Non-breeders move south to Perú into Humboldt Current. • ‡ ‡ Small numbers nest on Malpelo Island, off Colombia. Oversized eyes and white beak markings reflect nocturnal lifestyle.

Squid and deep-sea fish are main prey, captured at night.

Special note World’s only nocturnal gull is also unique in its pelagic lifestyle, feeding far out at sea, using enormous eyes to target squid and fish rising to the surface in darkness. In recent years, they have learned to follow ships, using disturbance from bow wave and glow from navigation lights to hunt.

Status • Although restricted in range, population apparently stable. Night’s catch — a large squid — is regurgitated and fed to hungry chick.

Unlike most other gulls, lays only one egg; attentive parents are very easily alarmed.

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Lava Gull

Larus fuliginosus Endemic Adult in flight; sexes alike.

Identification

• Ashy-gray body with dull black hood, primaries, beak, legs and feet; sexes identical. • White trim above and below eye, plus thin bright red eye ring, and vivid red inside lining of gape. • Juveniles gray-brown, scaly feather pattern on back. Active scavengers, here feeding on a sea lion placenta.

Understated breeding colors around eye and bill.

Natural History Coastal scavenger, living in pairs or small groups, roosting in salt lagoons. • Loud, drawn-out territorial “laughter” uttered with head arching up then bending down into a deep bow. • Pairs nest solitarily; two cryptically colored greenish eggs with black mottling laid in plant carpet or dead leaves; incubation 30 days; fledging around 2 months. • Chicks move away from nest and hide soon after hatching. Adult scavenging around Blue-footed Booby nest.

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Often seen on beaches, nearly always together in pairs.

Pairs regularly engage in raucous bouts of “laughing” calls.

Distribution • Present in small numbers throughout archipelago.

Chick departs nest within days of hatching.

Juvenile still begging for food.

Status • Rare, although often present around boats and towns. • Ground nester vulnerable to rats and cats. • Apparently stable, but only about 500 individuals total, making this the rarest gull in the world.

Immature mottled plumage.

Far left and below: Nests are well hidden among plants and rocks.

A sad but common story of breeding loss: Day 1: pair switch incubation (above right). Day 20: one egg is out of the nest (above left). Day 32 (inset): single chick hatches. Day 33: feral cat prowling, chick disappears.

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Sooty Tern Sterna fuscata Native Identification • Delicate, medium-sized, sharply demarcated black-and-white tern. • Buoyant flight, with powerful deep wingbeats. Species • Often screeches raucously in flight. characterized • Almost never seen in Galápagos other than by bold, blacknear Darwin Island, where it may approach and-white markings. nesting area from high above, screeching.

Natural History • Pelagic feeder, highly dependent on predatory fish to drive bait balls to the surface. • Nests in dense, very noisy colonies Small but tightly packed Darwin Is. nesting colony on the (below) is located high on the central plateau, amid ground. endemic Croton trees and surrounded by Redfooted Boobies. Mating (above) occurs in April–May. • Lays one egg, white with brown blotches.

Distribution • Only Galápagos colony located on summit plateau of Darwin Island. • Widespread in all tropical seas.

Status

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• Once-large colony on Darwin has dwindled or disappeared. • Decreasing in many regions due to overfishing of tuna, on which it depends to catch prey.

Evolved for a life on the wing. Feeds on fish and squid by surface dipping, but being unable to swim may not alight for years at a time.

Resting profile clearly shows exceptionally long wings.

Until the 1990s large flocks could still be seen returning to Darwin at sunset.

Brown Noddy

Anous stolidus

Endemic subspecies ‡ ‡ Identification • Elegant all-dark gray-brown with whitish forehead and cap, and white trim above and below eye. • Sexes identical; juvenile head all dark. • Only tern commonly seen in Galápagos.

Natural History

Typical stick nest on cliff ledge.

• Snatches small fish at or near sea surface, mainly near shore, often with other birds and predatory fish. • In particular has commensal relationship with Brown Pelicans, often perching on their heads, to snatch small fish either stunned from the pelican’s plunge dive, or escaping from its pouch. • Nest of small sticks and flotsam located on tiny ledges on sea-facing cliffs; lays one egg, white with brown blotches.

Distribution • Common around and between all islands. • ‡ ‡ Widespread in all tropical seas; distinct Galápagos subspecies is darker than others. Perching with Sally Lightfoot crabs.

Quick and agile in flight, the Brown Noddy is the largest of the 5 noddy species worldwide.

Rarely sits on water; slender shape distinctive from similarsized seabirds, and easy to identify.

Status • Abundant throughout the archipelago.

Often catches escaping fry from diving Brown Pelican’s beak, sometimes landing on their heads for a better lookout perch. Like many terns, feeds by partially plunging, snatching small fish often driven by predators below.

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Chilean Flamingo (Phoenicopterus chilensis)

Photo: © Monica Reck.

Since 2008 a pair (arrows below) periodically frequents the American Flamingo colony in the large saltwater lagoon at Punta Cormorant, Floreana Island. In 2017 they produced a chick (below left).

Salt lagoon habitat: Chilean Flamingo (distinctly paler bird on left) feeding alongside American Flamingo and 
White-cheeked Pintail. Chilean’s stockier build and yellow legs with reddish knees and feet are diagnostic.

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Part 3

Waders and Migrants

Part 2 Seabirds opening spread

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Great Blue Heron Ardea herodias Native ‡ ‡ Identification • Unmistakable; tall, pale gray heron with rufous thighs, black legs and crest, yellow bill. • Largest heron in Galápagos, by far. • Breeding birds develop wispy feathers on upper back and chest. • Juveniles mostly gray, with dark beak.

Natural History

Adult wingspan up to approx 2 m (6.5 ft); standing to height of 115–138 cm (45–54 in). Pale body plumage typical of Galápagos population.

• Seen fishing in salt lagoons, tide pools, mangrove fringes and rocky reefs, stalking prey with little movement. • Also hunts grasshoppers and lava lizards in coastal grasslands. • A voracious predator of hatchling marine iguanas and sea turtles. Below: Often seen • Nests, usually singly, in mangroves over water. Above: Patience and stealth hunting in lagoons, catching stalking lava lizards in tall grass. • Lays 2–3 pale blue-green eggs. prey with a sudden, sharp lunge or stab.

Keen-eyed and adept at cluing in to the slightest movement, may pull out sand eels or hatchling turtles from under the sand.

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Immature with streaky breast and dark beak, landing on lava rocks.

Other herons

Two vagrant species can very occasionally be seen in mangroves: Tricolored Heron (Egretta tricolor) (left) and Little Blue Heron (Egretta caerulea).

Distribution • Small numbers throughout Galápagos along shoaling shorelines. • Species ranges through North and Central America, and Caribbean.

Photo: © Monica Reck.

Catching young marine iguana.

Special note Galápagos race somewhat paler than elsewhere; considered a subspecies by some authors, A. h. cognata. ‡ ‡

Status • Conspicuous but uncommon in Galápagos. Sheltering pale green eggs in grass-lined nest.

Typical untidy stick nesting platform constructed over water in dense red mangroves. 109

Yellow-crowned Night Heron

Nyctanassa violacea pauper Endemic subspecies ‡ ‡ Identification

Male bathing in tide pool.

Natural History

Pre-fledging juvenile.

• Varies from dull brown (females and non-breeding) to beautiful slate-gray, with black-and-cream crest and long white nape feather. • Legs yellowish-green, depending on breeding condition; sturdy beak, all black. • Often seen awake in broad daylight. • Juveniles speckled and streaked gray, rusty brown and pale cream, with yellow on beak.

Giant centipedes, active at night, are • Lives mainly in or near mangroves, also other coastal a favored prey. vegetation, or in rocky clefts on bare shores. • Feeds on shoreline crabs and large insects inland. Distribution • Often seen flying Black-crowned Night Heron • Throughout Galápagos favors inland at dusk, where (Nycticorax nycticorax) dense coastal vegetation it hunts grasshoppers, and mangrove habitat. Rare sightings centipedes and mice. ‡ ‡ • Parent species range: since 1971; • Nests, well built of sticks, southern North America to first recorded concealed in mangrove northern South America. breeding by fringe, also other thickets Thalia Grant or under rock overhangs. Status in 2020. • Lays 2–3 greenish eggs. • Common in coastal regions. Photo: © Luis Die. Pair with male raising plumes in courtship.

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Well-camouflaged chicks in nest, begging for food from mother.

Lava Heron

Juvenile plumage.

Butorides sundevalli Endemic ‡ ‡

Female, with “striated” color tendencies.

Identification • Dark slate-gray with yellow or orange legs (breeding male); scaly wing coverts with green sheen, dark cap and greenishyellow legs (breeding female); all over duller when non-breeding. • Juveniles streaked cinnamon-brown, black and cream. • Smallest of the 3 Galápagos heron species.

Eating juvenile pufferfish despite poisonous skin.

Natural History • • • • •

‡ ‡ Debate exists whether this is an endemic species, subspecies, or just a color form of Striated Heron, B. striatus, with which it interbreeds. Snatching tiny mullet from red mangrove root perch. Entirely coastal, usually near mangroves and around rocky tide pools. Stalks small fish, shrimps or crabs by standing immobile, hunched above water’s edge, lunging rapidly with outstretched head, neck and beak. Nests well hidden in dense mangroves or other shoreline thickets. Lays 2–3 pale blue eggs.

Distribution • Found throughout Galápagos. • Striated Heron is widespread globally in tropical wetlands.

Status • Common.

Striated Heron

Subtle differences in breeding colors: male (above) and female (below).

(Butorides striatus) This species, considered by many to be synonymous with the Lava Heron, is also present in Galápagos, seen mostly around western Isabela and Fernandina Islands.

Preying on freshly molted Sally Lightfoot crab.

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Great Egret Ardea alba Native Identification • Large (but not as large as Great Blue Heron). • All white with dark greenish-black legs and yellow-orange beak. • Distinguishable from other egrets mainly by larger size, plus color of beak and legs.

Snowy Egret (Egretta thula) A regular visitor, smaller and slighter, with black beak and legs, but bright yellow feet.

Often seen roosting in mangroves.

Natural History • In years past, regularly nested in Galápagos, but more recently appears only as visitor. • Feeds on small fish in tide pools and lagoons, also insects in grasslands.

Distribution • Though uncommon in Galápagos, can turn up in any lagoon or shoreline. • Widespread in wetlands around the world.

Status Above and below: Different postures when stalking small fish trapped by high tides in mangrove lagoon.

Sharing a tide pool: Snowy Egret (at left) is distinctly smaller than Great. In Galápagos, preys mainly on fish, often using wings to scare fish into shallows (right).

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• Common species worldwide, though rare in Galápagos.

Cattle Egret Bubulcus ibis Native Day-old chick with egg.

Identification • The smallest and stockiest of the egrets, with greenish legs and yellow beak. • Usually seen in flocks in cattle pastures, or flying between highland feeding grounds and coastal nesting colonies. Thriving colony • May acquire rusty orange tinge prospecting nesting sites in on back when breeding.

Natural History

red mangroves of Santa Cruz.

• Originally an African species feeding in close association with large grazing mammals, has spread worldwide as humans replicated its native habitat with cattle farming; arrival in Galápagos mid-1960s. • Sometimes follows giant tortoises, or even sea lions while hunting horseflies and other insects. • Nests and roosts in a few very large colonies in thick mangroves, commuting to highlands to feed. Black legs / yellow beak diagnostic; brighter breeding colors.

Highly gregarious, flocks commute daily between highland feeding grounds and mangrove nesting areas.

Distribution • In Galápagos, mostly restricted to islands with cattle farming. • Worldwide distribution originating from Africa.

Status • Self-introduced in Galápagos, though some consider it a human-introduced species due to association with farming. Sometimes follows grazing tortoises disturbing insects.

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American Flamingo Phoenicopterus ruber Native

Elegant, upright stance: neck and legs are matched in length.

Identification • Unmistakable: tall and lanky, bright salmon-pink with black flight feathers (see paler Chilean Flamingo, p. 106). • Standing 1.45 m (43/4 ft) high, the tallest (but not heaviest) of four species found in the Americas. • Juveniles off-white or pinkish-gray; pale gray legs and beak. “Walking tall” group courtship. • Voice: loud, goose-like trumpeting.

Natural History

Feeds by rapidly pumping water with tongue, filtering out tiny invertebrates through 60–80 fine keratin blades that act as strainers.

Special note All flamingos (6 species worldwide) derive their pink color from carotenoid pigments produced by microscopic salt-loving algae, and passed up the food chain. The Galápagos population — the only one found in the Pacific Ocean — is renowned as one of the brightest colored (except for captive birds who may receive pigment supplements). Second largest species, only slightly smaller than Old World Greater Flamingo.

• Lives exclusively in saltwater lagoons near coast, which fluctuate in level according to tide and rains. • Filters tiny insects (mosquito larvae, waterboatmen), crustaceans and micro-algae through comb-like bill plates; like all flamingos, beak design with the lower mandible fixed is uniquely shaped to be used with head held upside down. • Often moves between islands searching for which lagoons have the best food concentrations. • Builds mud nests in small groups, laying single white egg, but often fails due to changing water levels or food supply.

Bathes regularly in deepest and freshest part of lagoons.

Groups nest together in close proximity in secluded locations, incubating a single egg in volcano-shaped nests built of mud.

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Flock moving between islands (Chilean Flamingo in lead). Groups regularly change lagoons in search of best food resources.

Landings can appear ungainly. Prime feeding and breeding habitat: the large saltwater lagoon at Punta Cormorant, Floreana.

Neck highly flexible.

Immature plumage grayish-pink.

Status Distribution

Sky-pointing courtship posture, very often performed in groups.

Typical scene of small group feeding.

• Found on islands and coasts of northern South America and Caribbean. • Species commonly seen in parks and zoos. 2-to-3-week-old chick in second down coat.

• Galápagos population, formerly about 400–500 birds, declining sharply in recent years. • Habitat loss due to rising sea level and El Niño flooding.

Males (here squabbling) are visibly larger than females.

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Paint-billed Crake Neocrex erythrops Native Identification • Secretive small rail, buff on back, bluish-gray below, with white barring on flanks and rump. • Bright yellow and red bill, and red legs instantly diagnostic. • Seen fleetingly, running across paths or flying short distance between low vegetation clumps. • Seen only in humid highlands, mostly along forest edge, rarely in mangroves. Bathing in shaded rain pool. Sometimes frequent tortoise wallows.

Nests discreetly located among thick vegetation.

Natural History • Feeds mainly on insects, and some grass seeds, often around pond edges. • Nests on ground under plant cover; lays 3–7 eggs. • Furtive behavior, difficult to observe.

Pairs or families most often seen dashing across muddy footpaths or roads in the inhabited highland regions.

Distribution • In Galápagos, occurs in partly wooded highlands, usually near water. • Ranges throughout tropical Central and South American wetlands.

Status

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• Probably more common than it appears, due to secretive nature. • Has not been studied in Galápagos; very little known about this species from other areas.

Common Gallinule Gallinula galeata Native

Identification

Pair sharing aquatic vegetation.

Natural History

• A shy, plump, dark gray bird with long, red and yellow legs and beak. • Lives around permanent ponds and marshes, fresh or brackish. • Flashes white under-tail feathers when alarmed. • Disappears with loud alarm call among reeds at first sign of danger. • Avoid confusing with Purple Gallinule (see box).

• A marsh bird, never seen far from water. • Lives in extended family groups, which include adult offspring. • Feeds on aquatic plants. • Although rarely flies, has uncanny ability to find wetlands even when newly formed (e.g., lakes in Fernandina and Cerro Azul calderas).

Purple Gallinule (Porphyrio martinicus) Avoid confusion of the native Common Gallinule with the Purple Gallinule, a rare vagrant from Central and South America.

Distribution • In Galápagos, restricted to permanent fresh and brackish pools. • Widespread in North and South American wetlands. • Similar species known as Moorhen in the Old World.

Status • Widespread and common. • In Galápagos, distribution limited by availability of standing water sources. Parent with small chick (far left) and juvenile (below).

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Galápagos Rail Laterallus spilonotus Endemic Identification • A tiny ground bird scuttling secretively beneath dense undergrowth. • More often heard (loud staccato call) than seen. • Slate-gray with rusty blaze around Pair sharing incubation on nest located in dense grass clump. nape; finely speckled white. • Black legs and beak; bright red eyes. • Sexes similar, but female may have paler throat. • Difficult to see, but curious and may approach a prone person closely without emerging from thickets.

Natural History • Lives mainly in mossy understory or dense grass and bracken fields in misty parts of highlands. • Nearly flightless; flies rarely, only short distances, low to ground. • Feeds mainly on invertebrates, foraging by probing into leaf litter, moss beds, etc. Rarely completely leaves the security of dense undergrowth (above). However, naturally • Nests on ground, in grass or fern clumps. curious, so will often approach an • Pairs travel with small chicks, making constant low contact calls. observer sitting quietly (below).

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Photo: © Ian Henderson.

Small chicks run around freely following their parents but regularly huddle for warmth in the cool, misty environment typical of their highland habitat.

Distribution • Occurs mainly in humid highlands, especially dense fern and grassland habitat. • Found on Santa Cruz, Santiago, Pinzón, Pinta, rare on Isabela and Fernandina.

Feeding large native cricket to chicks.

Status • Severe predation by feral rats, cats, pigs and dogs. • Extinct on Floreana and San Cristóbal. • Population rebounded on Santiago and Pinzón after pig and rat eradications, respectively.

Though still able to fly short distances, diminutive wings are rarely used, an evolutionary trait typical of ground-dwelling birds that are endemic to remote island ecosystems where there are no native mammalian predators.

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White-cheeked Pintail

Female (in flight) has paler red on beak than male (walking); green speculum clearly visible.

Anas bahamensis galapagensis Endemic subspecies ‡ ‡

Breeding male.

Identification • Also known as Bahama Pintail, a dainty, mostly brown duck with pale cheeks and green speculum. • Red base of beak more pronounced in males than females. • Markings, especially white cheeks, less distinct than South American and Caribbean races. • Unmistakable, only permanent resident duck in Galápagos. Dabbles like most ducks.

Natural History • Eats small invertebrates in fresh and saltwater pools, but requires sources of freshwater to drink. • Lays up to 10 pale brown eggs hidden in ground vegetation. • Regularly travels between islands to find best feeding ponds. • Often feeds alongside flamingos. • Breeds around permanent fresh and brackish-water pools. • Sometimes learns to eat corn with farm poultry (Floreana); visits some hotel swimming pools.

Sometimes found in mangrove thickets.

Often shares saltwater lagoons with flamingos and other waders. Commonly seen frequenting nutrient-rich tortoise ponds in highlands that support thriving aquatic invertebrate populations.

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Some of the largest pintail concentrations reside on the mineral-rich lake inside the regularly active Fernandina caldera.

Distribution

Exceptionally large clutch of juveniles still following mother.

• Most numerous on Fernandina caldera lake, despite periodic volcanic eruptions. • ‡ ‡ Two other subspecies, Greater and Lesser Bahama Pintails, found in South America and Caribbean, respectively.

Ducklings feeding under mangroves in saltwater pond.

Photos x 2: © Juan Salcedo.

Status

A vagrant male Greater Bahama Pintail, A. b. rubirostris (indicated by arrows), is much larger and more colorful than native male (below at right), and successfully bred with local female in 2021 (above).

• Galápagos population stable despite mass mortality events during periodic Fernandina volcanic eruptions.

Survival rate of chicks usually very low.

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American Oystercatcher Haematopus palliatus Native Identification • A large black-and-white shorebird with massive red beak and pale pink legs. • Bright yellow iris with red eye ring. • Usually seen in pairs, cannot be mistaken for any other bird in Galápagos.

Conspicuous white bars on black wings.

Natural History • Found along sandy and rocky shores, resting at high tide, actively working rocky foreshore at low tide. Loud ecstatic courtship call performed together. • Feeds on crabs, snails, sea urchins, etc., pried from rocky fissures with powerful, vertically flattened beak. • Sometimes also hunts sand crabs by probing wave-washed beaches. • Nests among driftwood and shells on beaches above high tidemark. • Usually lays two heavily mottled greenish-gray eggs. • Pairs stay together even Nest consists of simple shallow scrape in sand. when not nesting, reuniting Distribution after brief separations with Nest with egg and hatchling. loud display. • In Galápagos, can be seen along most protected shorelines, but absent in western islands. Status • Widespread in coastal environments of North, Central and • Uncommon in Galápagos. South America, and Caribbean. Found mainly in pairs wandering along shorelines at low tide, feeding methodically on a wide variety of marine invertebrates.

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Black-necked Stilt Himantopus mexicanus Native Almost always calls while in flight.

Identification

• Dainty, long-necked, black-and-white shorebird strutting purposefully on impossibly thin, bright pink legs. • Needle-like beak black; conspicuous white patch above eye. • Somewhat shy and very noisy when alarmed, circling with incessant, piercing “pip-pip-pip-pip” call. Pair, busily picking up • Usually seen in pairs or family groups with one to two fledglings. tiny crustaceans along beach. • Feeds on tiny organisms almost exclusively in salty, brackish or freshwater pools, rarely in tide pools. • Two mottled, dark greenish eggs laid in wellcamouflaged ground nest near edge of salt pond.

Distribution

With giant tortoise in nutrientrich highland rain pond.

Photos x 2: © Monica Reck.

Natural History

Precocial chicks wander freely under close protection of parents.

• Commonly found in all coastal lagoons of Galápagos, sometimes rain ponds in highlands. • Widespread in North and South America and Caribbean.

Status • Widespread and common. Immature showing paler neck.

Often feeds alongside flamingos.

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Visitors from afar Because of its location, some 1,000 km (620 mi) off the equatorial coast of South America, no migrant seabirds make the Galápagos Archipelago their specific destination, although many incidental species have been recorded in offshore waters, at the edges of their respective pelagic ranges in the South Pacific. However, a few migratory shorebirds do make regular stopovers on their way from northern breeding grounds to their wintering locations in southern South America. Some individuals even spend their entire northern winter here, while several others show up only occasionally as accidental vagrants. I have therefore chosen to include only a small sampling of those birds most likely to be seen. Identification is often complicated by dull winter plumages, immature coloration, worn feathers, or a combination of all three.

Competition with Galápagos residents: Vagrants, such as this Franklin’s Gull (Leucophaeus pipixcan) seen here trying to steal small bait fish escaping from a Brown Pelican’s pouch, have trouble competing with residents such as Brown Noddies.

Whimbrels (Numenius phaeopus): Migrate across Galápagos in small, fast flocks, many heading for estuary flats in southern Chile. Individuals sometimes make lengthy stopovers and can be seen year-round feeding around lagoons and along Galápagos beaches.

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Rarely sighted seabirds Clockwise from top left: Royal Tern (Sterna maxima) mainly feeding along surf-beaten beaches. Arctic Tern (Sterna paradisaea) in dull non-breeding plumage, stopping off briefly during one of the longest migrations between the Arctic and Antarctica. Inca Tern (Larosterna inca) occasionally straying up from the cold upwelling waters of the Humboldt Current along coastal Perú and Chile. Pintado Petrel (Daption capensis) sometimes ranging north from cold Southern Ocean waters.

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Whimbrel (Numenius phaeopus) • Large shorebird with speckled buff-brown plumage; easily recognized long decurved bill. • Regular visitor from northern tundra breeding grounds, flocks passing through on their way to southern South America; some remain year-round. • Can be seen on beaches, salt lagoons, rocky shores; also in highland grasslands, hunting invertebrates.

Wandering Tattler (Tringa incana) • A busy little gray bird with yellow legs, often seen dodging waves along exposed rocky shores, hunting small crabs. Winter plumage uniform gray with white belly; speckled summer plumage (below left) rarely seen. Almost always emits rapid twiddling call on takeoff. • Regular visitor from northern North America, usually in dull gray winter plumage (below right).

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Ruddy Turnstone (Arenaria interpres) • Most colorful and commonest regular migrant, seen singly or in flocks, along rocky and sandy seashores alike. • Some habituated to picking grain and other tidbits on cargo docks and in town squares.

Willet (Tringa semipalmata) • A large, slender wader with straight bill. Dull gray-brown and white; easy to identify in flight by black-and-white wing markings. • Rare visitor to salt lagoons.

Lesser Yellowlegs (Tringa flavipes)

• Taller, slimmer, paler and more speckled than Wandering Tattler. • Rare visitor to salt lagoons. • More robust Greater Yellowlegs is even rarer.

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Semipalmated Plover (Charadrius semipalmatus) • Small and compact, with conspicuous black neck band and eye mask. Short legs and very short beak. • Commonly seen along the edges of saltwater flamingo lagoons, rarely in freshwater ponds with giant tortoises. • Nests in Arctic tundra.

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Black-bellied Plover (Pluvialis squatarola)

White-rumped Sandpiper (Calidris fuscicollis)

• A large, stately plover. Winter plumage lacks all trace of black breast; dull speckling on back. • Rare visitor, usually along wide beaches, such as Villamil (Isabela). • Circumpolar nesting in the High Arctic.

• Boldly spotted, slightly larger than other sandpipers. Dark bill slightly curved, paler in juvenile; blackish legs. • Rare visitor; migrates mostly along eastern Americas, east of the Rockies and the Andes. • Nests primarily in the eastern Canadian Arctic.

Sanderling (Calidris alba) • Predominantly white, with conspicuous wing bars in flight. • Feeds on beaches, often in flocks, running ahead of the wave edge like wind-up toys. • Circumpolar nesting across High Arctic coastal tundra, with cosmopolitan distribution around most of the world’s marine coastlines.

Least Sandpiper (Calidris minutilla)

• Small, pale shorebird, lacking body spots of summer; small spots only on upper wing. Dark bill straight, clear eye line; dull yellowish legs. • South American migrant; rare in salt lagoons. • Nests throughout North American tundra.

• Tiny little bird; scale-like brown markings on back and head, darker than summer plumage; black bill very slightly drooping; yellow-green legs. • Seen in small groups feeding in salt lagoons or along rocky shores. • Nests in North American tundra.

Photo: © Monica Reck.

Spotted Sandpiper (Actitis macularius)

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Red-necked Phalarope (Lobipes lobatus) • The only migrant targeting Galápagos in large numbers. • Large flocks feed on plankton in open waters between islands March–August. • Unusual among waders by wintering in tropical open seas around the world, nesting in High Arctic. • Sometimes called Northern Phalarope.

Red Phalarope (Phalaropus fulicarius) (right) • Winter plumage very similar to Rednecked Phalarope, but generally darker. • Frequents salt ponds rather than open sea.

Wilson’s Phalarope (Phalaropus tricolor) (below) • Palest of three migrant phalaropes with noticeable pale eye stripes. • Often seen in small flocks on salt lagoons.

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Franklin’s Gull (Leucophaeus pipixcan) • Most commonly seen migrant gull, hard to distinguish because of combination juvenile and winter plumage. • Note small size, white wing trim, black ear patches. • Often seen with Lava Gulls and Brown Noddies. • Breeds central North America, winters west coast of South America.

Laughing Gull (Leucophaeus atricilla) (right) • Larger than Franklin’s, longer beak, no white on flight feathers. • Breeds Atlantic coast of North America, Caribbean and Central America.

Kelp Gull (Larus dominicanus) (below) • Large, boldly marked; loud laughing call. • Ranges southern South America and Antarctica. Rare vagrants may settle for years (e.g., Plazas), very destructive to nesting Swallow-tailed Gulls (below).

Below: Kelp Gull harassing alarmed nesting Swallow-tailed Gull.

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Nesting Darwin’s Flycatchers: Dedicated parents caring for tiny chicks in a cup-shaped nest intricately camouflaged in mosses (Isabela). Formerly named the Galápagos or Little Vermilion Flycatcher, this is the latest of several species to be recognized as true Galápagos endemics. 132

Glossary

Selected key terms used throughout the text

• Arboreal: living in trees. • Caldera: oversized, generally flat-floored craters in the center of large shield volcanoes, caused by collapse rather than explosion. • Circumpolar: found around the polar region. The Galápagos subspecies of • Commensal / commensalism: an association between two organisms Short-eared Owl is very often diurnal, especially where in which one benefits and the other derives neither benefit nor harm. Galápagos Hawks • Conspecific: two or more species sharing the same living space. are absent. • Dimorphic / dimorphism: two different forms or colors of the same species, e.g., Red-footed Boobies. • Diurnal: active during daytime (i.e., opposite of nocturnal). • Dynamic soaring: a specialized form of gliding flight used by albatrosses and large petrels over the ocean, rising and dropping over the waves, using the wind’s power to travel with little energy expenditure. • El Niño / La Niña: climatic phenomena when oceanic sea surface temperatures are either considerably above / below normal, causing ecological disruption if prolonged (see climate explanation p. 13). • Endemic: found only in the location given. • Endemic subspecies: a species found in other locations, but sufficiently different to be regarded as locally distinct. • Gadfly petrel: a group of about 35 species of large, narrow-winged petrels, named for their speedy, weaving flight, belonging to the genus Pterodroma. • Garúa: local name for wind-driven mist precipitating as fine drizzle during the cooler southern winter, nurturing lush cloud forests in some areas. • Intertidal: areas of rocky or sandy seashore normally covered or exposed by daily tides. • Introduced or feral: brought to the islands by humans, but since gone wild (cf. Native). • Native: occurring naturally, but also found breeding elsewhere (cf. Endemic, Introduced) • Pelagic: feeding and ranging in the open ocean. • Polyandry / polyandric: a relatively rare breeding system in which a single female may mate with several males; in cooperative polyandry (e.g., Galápagos Hawks), all males help raise the chicks • Raptor: a carnivorous bird of prey with hooked beak and sharp talons, e.g., hawks, eagles and owls. • Siblicide: where an older chick kills its younger sibling; obligate siblicide is when this behavior is inevitable. Parents do not interfere with the process. • Speculum: secondary wing feathers in ducks, with brilliant refracted sheen, usually blue or green. • Tundra: treeless expanse in the Arctic characterized by permanently frozen ground beneath a thinly vegetated surface. • Upwelling: a process where strong, wind-driven ocean currents force cold, nutrient-rich deep water to the surface, resulting in “fertilized” areas of high biological productivity. • Vagrant: species that appears outside of its normal range, possibly lost. • Vegetation Zones: Arid Zone: lowlands and coastal areas, where little or no rain falls during much of the year. Transitional Zone: receiving more rain than the lowlands, but below the mist layer. Highlands: where mist (cf. Garúa) is pushed by winds against the higher slopes above 200 m (655 ft) causing variable amounts of rain that maintain green vegetation year-round. 133

Index

bolding = main reference

Alcedo Volcano (Isabela) 14, 48; Map 10. American Oystercatcher 9, 122. Audubon Shearwater 79. avian pox & pathogens 17, 26, 75. Bahama Pintails; Greater & Lesser 121; See also White-cheeked Pintail. Bartolomé Island; Map 10,13. Black-bellied Plover 128. Black-necked Stilt 9, 123. boobies 9, 54. Blue-footed Booby 8, 9, 84–85, 93, 102, 136; Map 10–11. Brown Booby 88. Masked Booby 88, 89. Nazca Booby 55, 88–89; Map 10–11. Red-footed Booby 55, 86–87, 91, 104, 133; Map 10–11. Brown Pelican 9, 70–71, 72, 73, 74, 98–99, 105, 124. cactus 58, 64, 65. Jasminocereus 48. Opuntia 6, 26, 29, 34, 45, 46, 51, 53, 54, 56, 57, 59, 96. Cerro Azul Volcano (Isabela) 117. Champion Islet (Floreana) 29, 96; Map 10. Charles Darwin Research Station 17, 63, 136. Chile 78, 81, 82, 124, 125; Map 10, 12. climate change 75, 85. climate & seasons 12–13, 29, 34, 35, 41, 43, 45, 53, 74, 75, 78, 85, 133. Clipperton Atoll 89. Cocos Island Finch 42; Map 10. Common Gallinule 9, 117. Daphne Islet 6, 7, 49; Map 10, 13. Dark-billed Cuckoo 36. Dark-rumped Petrel; See Galápagos Petrel. Darwin, Charles 9, 24, 42, 51. Darwin Island 42, 46, 55, 70, 87, 89, 91, 104; Map 10. Darwin’s Finches 6, 7, 8, 9, 16–17, 40–47, 66, 68. “Big Bird” 6. Common Cactus Finch 6, 29, 40, 45, 46, 56–57, 59, 64. Española Ground Finch 40, 46, 58. Genovesa Cactus Finch 40, 46, 58, 59. Genovesa Ground Finch 40, 46, 53, 55. Gray Warbler Finch 40, 47, 68, 69. Green Warbler Finch 40, 47, 68, 69. Large Cactus Finch; See Española Ground Finch. Large Ground Finch 16, 40, 43, 46, 49, 50–51, 54, 58. Large Tree Finch 40, 43, 47, 62. Mangrove Finch 40, 47, 63, 64. Medium Ground Finch 6, 16, 40, 41, 42, 43, 44, 46, 49, 50, 56. Medium Tree Finch 40, 43, 47, 61. Sharp-beaked Ground Finch 40, 46, 52, 54, 55. Small Ground Finch 16, 40, 42, 43, 45, 46, 48, 53. 134

Small Tree Finch 41, 43, 47, 60. Vampire Finch 9, 40, 46, 54–55. Vegetarian Finch 40, 44, 45, 47, 62, 66–67. Woodpecker Finch 40, 43, 47, 63, 64–65. dimorphism 86, 133. Dull-colored Grassquit 42. El Niño / La Niña 13, 75, 77, 95, 115, 133. Española Island 24, 25, 28, 29, 40, 42, 46, 47, 58, 59, 69, 77, 89, 91, 101; Map 10, 13. Feral Chicken 38. Fernandina Island 11, 40, 46, 47, 74, 95, 111, 117, 119, 121; Map 10, 13. finches; See Darwin’s Finches. fish (as prey) 48, 54, 55, 70, 74, 79, 80, 83, 84, 87, 89, 90, 94, 96, 97, 98, 99, 101, 104, 105, 108, 111, 112, 124. flamingos American Flamingo 9, 106–107, 114–115, 120, 123; Map 10–11. Chilean Flamingo 106, 114, 115. Flightless Cormorant 4–5, 9, 12, 72, 94–95; Map 10–11. Floreana Island 18, 21, 23, 25, 29, 35, 40, 46, 47, 51, 57, 61, 67, 74, 78, 87, 91, 93, 96, 106, 115, 119, 120; Map 10, 13. flycatchers Darwin’s Flycatcher 31, 32–33, 132. Galápagos Flycatcher 31, 32. Little Vermilion (Galápagos) Flycatcher; See Darwin’s Flycatcher. frigatebirds 90, 92, 100. as pirates 86, 93, 96, 97. Great Frigatebird 90–91, 92; Map 10–11. Magnificent Frigatebird 90, 92–93; Map 10–11. Galápagos Dove 16, 34–35. Galápagos Martin 37. Galápagos National Park Directorate 17, 136. Galápagos Petrel 9, 12, 72, 78; Map 10–11. Galápagos Rail 9, 16, 118–119. Galápagos sea lion 30, 75, 92, 102. Galápagos Shearwater 72, 78, 79, 93. Galapagos snake 16, 45. Gardner Islet (Floreana) 29, 87, 89, 91, 93; Map 10, 13. garúa 13, 35, 58, 133. Genovesa Island 18, 31, 40, 42, 46, 47, 50, 51, 53, 58, 59, 82, 87, 89, 91, 93, 100, 101; Map 10, 13. giant tortoises 18, 19, 28, 34, 35, 38, 48, 113, 116, 123, 128. Grant, Drs. Peter & Rosemary 6, 7, 8, 136. Grant, Thalia 110. Greater Flamingo 114. gulls Franklin’s Gull 124, 131. Kelp Gull 131. Laughing Gull 131. Lava Gull 9, 72, 102–103, 131. Swallow-tailed Gull 12, 73, 100–101, 131; Map 10–11.

Harris, Dr. Michael 40. Hawaiian Petrel 72. hawks Galápagos Hawk 14–15, 16, 17, 18–19, 45, 100, 133. Swainson’s Hawk 19. herons & egrets Black-crowned Night Heron 110. Cattle Egret 113. Great Blue Heron 108–109, 112. Great Egret 112. Lava Heron 111. Little Blue Heron 109. Snowy Egret 112. Striated Heron 111. Tricolored Heron 109. Yellow-crowned Night Heron 110. insects (as prey) 8, 16, 18, 19, 21, 23, 26, 27, 29, 30, 31, 32, 36, 37, 38, 39, 42, 43, 45, 47, 48, 51, 54, 60, 61, 62, 63, 64, 65, 68, 69, 108, 110, 111, 112, 113, 114, 116, 126. introduced predators 16, 39, 51, 119. cat 34, 35, 51, 78, 103, 119. dog 78, 119. mouse 20, 22, 38, 110. pig 78, 119. rat 22, 35, 47, 51, 63, 78, 103, 119. Isabela Island 11, 18, 37, 40, 46, 47, 48, 60, 62, 63, 64, 66, 74, 78, 93, 95, 111, 119, 128, 132; Map 10, 13. Isla de la Plata (Ecuador) 11, 73, 77, 89; Map 10. land snails (as prey) 52. Malpelo Island (Colombia) 73, 89, 101; Map 10. Marchena Island 40, 47, 62; Map 10, 13. marine iguana 19, 48, 75, 95, 108, 109. marine invertebrates (as prey) 94, 110, 111, 114, 122, 123, 126. squid 78, 96, 100, 101, 104. México 82, 85, 89. mockingbirds 24–29. Española Mockingbird 24–25, 28. Floreana Mockingbird 25, 29. Galápagos Mockingbird 9, 24, 26, 27. San Cristóbal Mockingbird 25, 27. ocean currents; Map 12. Cromwell Current 11, 12, 72, 74, 95. Humboldt Current 12, 73, 77, 101, 125. upwellings 12, 13, 72, 73, 74, 77, 95, 125, 133. orca (killer whale) 81, 92. Osprey 14, 18. owls 8, 9, 16, 45, 100. Barn Owl 21, 22–23. Short-eared Owl 20–21, 82, 83, 133. Paint-billed Crake 9, 116. penguins African Penguin 75. Galápagos Penguin 9, 12, 72, 74–75; Map 10–11. Humboldt Penguin 75. Magellanic Penguin 75. Peregrine Falcon 14, 18. Perú 77, 78, 81, 85, 101, 125; Map 10, 12.

phalaropes Northern Phalarope; See Red-necked. Red-necked Phalarope 130. Red Phalarope 130. Wilson’s Phalarope 130. Pintado Petrel 125. Pinta Island 30, 40, 46, 47, 51, 52, 62, 119; Map 10, 13. Pinzón Island 26, 30, 40, 47, 119; Map 10, 13. plants; See also cactus. Bursera (palo santo) 19, 51. Cordia lutea (muyuyo) 27, 45, 50, 66, 67. Croton 104. Cryptocarpus (saltbush) 67, 91, 93, 98. Erythrina velutina (caco) 41, 50, 57, 60, 62, 66. Hippomane mancinella (manzanillo or poison apple tree) 67. introduced pest species 21. Iochroma elliptica 62. leaves, flowers, fruits & seeds (as food) 26, 27, 28, 29, 31, 34, 38, 41, 42, 43, 45, 48, 49, 50, 51, 53, 54, 56, 57, 58, 59, 60, 61, 62, 66, 67, 68, 69, 116, 117. mangroves 9, 30, 47, 63, 70, 75, 93, 98, 108, 109, 110, 111, 112, 113, 116, 120, 121. Maytenus octogona 45, 50. Miconia 68. Parkinsonia 60. Passiflora foetida (passionflower) 50. Prosopis juliflora 57. Scalesia cordata 62. Scutia 43. Tribulus 28, 50, 58, 69. Plazas Island 83, 131; Map 10, 13. polyandry 19, 94, 133. Punta Cormorant 106, 115; Map 10. Punta Pitt (San Cristóbal) 87; Map 10. Purple Gallinule 117. Rábida Island 40, 47; Map 10, 13. raptors; See individual species. Red-billed Tropicbird 96–97; Map 10–11. reptiles (as prey) 19, 28, 38, 108, 109. Revillagigedos (Mexico) 89. Roca Redonda 82; Map 10. Ruddy Turnstone 127. Sally Lightfoot crab 30, 105, 111. salt lagoons 9, 102, 106, 108, 114, 115, 120, 123, 126, 127, 128, 129, 130. San Cristóbal Island 8, 18, 25, 27, 33, 35, 40, 46, 47, 64, 78, 87, 91, 93, 119; Map 10, 13. Sanderling 129. sandpipers, Least Sandpiper 129. Spotted Sandpiper 129. White-rumped Sandpiper 128. Santa Cruz Island 7, 16, 18, 38, 39, 40, 46, 47, 48, 49, 50, 56, 57, 60, 62, 63, 64, 65, 66, 67, 68, 78, 113, 119; Map 10, 13. Santa Fe Island 21, 40, 47; Map 10, 13. Santiago Island 34, 40, 46, 47, 52, 68, 74, 78, 119; Map 10, 13. sea turtles (as prey) 19, 28, 81, 108. Semipalmated Plover 128. Seymour Island 40, 93; Map 10, 13. siblicide 133.

Smooth-billed Ani 39. storm petrels as prey 20, 82, 83. Band-rumped Storm Petrel 83. Elliot’s Storm Petrel 81. Galápagos Storm Petrel; See Wedge-rumped Storm Petrel. Madeiran Storm Petrel; See Band-rumped Storm Petrel. Wedge-rumped Storm Petrel 20, 82, 83; Map 10–11. White-vented Storm Petrel 80–81, 82. Tagus Cove (Isabela) 37; Map 10. Tebbich, Dr. Sabine 8, 136. terns Arctic Tern 125. Brown Noddy 105, 124, 131. Inca Tern 125. Royal Tern 125. Sooty Tern 104; Map 10–11. Tortuga Islet 93; Map 10. trade winds 13; Map 12. vampire fly (Philornis downsi) 17, 30, 31, 33, 47, 60, 63, 68. Wandering Tattler 126, 127. Waved Albatross 9, 12, 72, 73, 76–77; Map 10–11. Whimbrel 124, 126. White-cheeked Pintail 9, 106, 120–121. Willet 127. Wolf Island 31, 40, 42, 46, 54, 55, 70, 87, 89, 91, 93; Map 10. Yellowlegs, Lesser & Greater 127. Yellow Warbler 8, 30.

Scientific bird names index

Actitis macularius 129. Anas bahamensis galapagensis 120. Anas bahamensis rubirostris 121. Anous stolidus 105. Ardea alba 112. Ardea herodias 108. Arenaria interpres 127. Asio flammeus galapagoensis 20. Bubulcus ibis 113. Buteo galapagoensis 18. Butorides striatus 111. Butorides sundevalli 111. Calidris alba 129. Calidris fuscicollis 128. Calidris minutilla 129. Camarhynchus heliobates 47, 63. Camarhynchus pallida 47, 64. Camarhynchus parvulus 47, 60. Camarhynchus pauper 47, 61. Camarhynchus psittacula 47, 62. Certhidea fusca 47, 69. Certhidea olivacea 47, 68. Charadrius semipalmatus 128. Coccyzus melacoryphus 36. Creagrus furcatus 100. Crotophaga ani 39. Daption capensis 125. Egretta caerulea 109. Egretta thula 112. Egretta tricolor 109. Falco peregrinus 14.

Fregata magnificens 92. Fregata minor 90. Gallinula galeata 117. Gallus gallus 38. Geospiza acutirostris 46, 53. Geospiza conirostris 46, 58. Geospiza difficilis 46, 52. Geospiza fortis 6, 46, 49. Geospiza fuliginosa 46, 48. Geospiza magnirostris 46, 50. Geospiza propinqua 46, 59. Geospiza scandens 6, 46, 56. Geospiza septentrionalis 46, 54. Haematopus palliatus 122. Himantopus mexicanus 123. Larosterna inca 125. Larus dominicanus 131. Larus fuliginosus 102. Laterallus spilonotus 118. Leucophaeus atricilla 131. Leucophaeus pipixcan 124, 131. Lobipes lobatus 130. Mimus macdonaldi 25, 28. Mimus melanotus 25, 27. Mimus parvulus 24, 26. Mimus trifasciatus 25, 29. Myiarchus magnirostris 31. Neocrex erythrops 116. Numenius phaeopus 124, 126. Nyctanassa violacea pauper 110. Nycticorax nycticorax 110. Oceanites gracilis galapagoensis 80. Oceanodroma castro 83. Oceanodroma gracilis gracilis 81. Oceanodroma tethys kelsalli 82. Oceanodroma tethys tethys 82. Pandion haliaetus 14. Pelecanus occidentalis urinator 70, 98. Phaethon aethereus 96. Phalacrocorax harrisi 94. Phalaropus fulicarius 130. Phalaropus tricolor 130. Phoebastria irrorata 73, 76. Phoenicopterus chilensis 106. Phoenicopterus ruber 114. Pinaroloxias inornata 42. Platyspiza crassirostris 47, 66. Pluvialis squatarola 128. Porphyrio martinicus 117. Progne modesta 37. Pterodroma phaeopygia 78. Puffinus subalaris 79. Pyrocephalus dubius (extinct) 33. Pyrocephalus nanus 32. Setophaga petechia aureola 30. Spheniscus mendiculus 74. Sterna fuscata 104. Sterna maxima 125. Sterna paradisaea 125. Sula dactylatra 89. Sula granti 88. Sula leucogaster 88. Sula nebouxii 84. Sula sula 86. Tiaris obscurus 42. Tringa flavipes 127. Tringa incana 126. Tringa semipalmata 127. Tyto alba punctatissima 22. Zenaida galapagoensis 34. 135

Acknowledgments The Galápagos Islands have been my home, my classroom and my source of joy and inspiration for the past 60+ years. But such deep connection and insight did not come without the input of innumerable people who helped me understand and appreciate what surrounded me since early childhood. While it is impossible for me to individually name every wonderful person who — both institutionally and personally — has supported my work as a photographer, naturalist and writer, I would like to collectively thank all the people who enriched and enlightened me in the field of Galápagos ornithology. This includes the tireless conservation officials of the Galápagos National Park Directorate and researchers at the Charles Darwin Research Station, as well as many other scientists who, over decades, have come to study these islands’ avifauna and shared their knowledge freely. Equally crucial are the numerous visitors who provide the underpinning values to preserve Galápagos. Moved by the uniqueness and fragility of these islands, these people have donated indispensable resources to support the complex, expensive and laborious work required to safeguard the wildlife and ecosystems of Galápagos. I therefore feel a deep appreciation for all who care about these islands and lend their support toward maintaining their natural integrity. Between you, you’ve shared your knowledge, enthusiasm, generosity and discoveries freely, and at the same time have supported me in my never-ending quest to access the remotest corners of this archipelago. This book is the sum of your countless contributions. Thank you one and all! Special thanks go to the following people for their direct input into this little volume, providing critique and observations, sharing details on distribution records and special behaviors, supplying photos of rarely seen species, or simply making constructive comments about content: Peter and Rosemary Grant, Birgit Fessl, Michal Dvorak, Sabine Tebbich, David Anchundia, David Anderson, Juan Salcedo, Luis Die, Monica Reck, and not least, young Ian Henderson for his remarkable photo of a Galápagos rail briefly flitting through a ray of sunlight. In closing, heartfelt thanks to my partners in Roving Tortoise Photography: Mark Jones for his meticulous attention to detail, going far beyond the purvey of most designers, and to Julie Cornthwaite for her analytical proofreading and critique. And to Robert Kirk and his editorial team at the Princeton University Press, a huge “Thank You” for being so delightful to work with.

Equatorial sunset: At the end of a busy day fishing, Blue-footed Boobies gather to roost for the night on a bouldery lava shore.

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