Sea Turtles of Hawai`i 9780824842093

Citation preview

Sea Turtles of Hawai'i

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Science AËvis

© 2001 University of Hawai'i Press All rights reserved Printed in China 17

10 9 8 7

Library of Congress Cataloging-in-Publication Data Ching, Patrick. Sea turtles of Hawai'i / Patrick Ching. p. cm. Includes bibliographical reference (p. ). ISBN-13: 978-0-8248-2434-1 (alk. paper) 1. Sea turtles—Hawaii. I. Title. QL666.C536 C45 2001 597.92'817749—dc21

2001027911

All hand-drawn illustrations were created by the author. Front cover and Dedication page art by Patrick Ching, inspired by a photograph by Monte Costa. Title page photo © Michael S.

Nolan/www.wildlifeimages.net

University of Hawai'i Press books are printed on acid-free paper and meet the guidelines for permanence and durability of the Council on Library Resources.

Designed by Santos Barbasa Jr. Printed by Everbest Printing Co., Ltd.

f*

Introduction

1

Growing, Grazing, and the Span of Life

26

Lasting Impressions

3

N a t u r a l Neighbors

27

In the Name of the Honu

4

Trials of Life, Causes of Death

28

Royalty, Religion, and the Mystical Honu

5

Ancient Kapu to Modern Law

30

Evolving through Depth and Time

6

Mysterious Tumors

32

Sea-turtle Anatomy

7

Additional Threats

34

The Loggerhead

8

Native Gathering

37

The Olive Ridley

10

Modern Conservation

39

The Leatherback

12

In the Public Eye

41

The Hawksbill or 'Ea

14

The Power of Education

43

The Hawaiian Green Turtle or Honu

16

Sharing Sand and Sea

44

Gathering on the Shoals

18

In the Spirit of Aloha

46

Sex and Mating

21

Photo Album

48

Nesting

22

Incubation and Hatching

24

Acknowledgments (Mahalo)

53

The Trek to the Sea

25

Suggested Reading

55

•d to all of you take the world od's creatures

Aloha. I'm Patrick Ching. Mabalo (thank you) for opening this book. If you're reading this, it probably means you like nature, animals, or at least sea turtles. Well, you're not alone. Many folks are enamored with these dynamic creatures. What's not to like about them? They're beautiful, ancient, and graceful; plus they're harmless to people and a joy to be around. Growing up in Hawai'i, and being the water rat that I am, I've been around sea turtles a long time. The things I've learned and heard about turtles have made me want to find out more. The inspiration for writing this book came soon after I opened Naturally Hawaiian, a nature gallery, gift shop, and art school in Waimanalo, on O'ahu. I was amazed at the interest that my customers and art students had in Hawai'i's sea turtles. Having lived with sea turtles on remote Hawaiian atolls, I was able to answer most of their questions, but not all. When I tried to look up information on Hawai'i's turtles, I found that there was no book exclusively about sea turtles of Hawai'i. I also came across some literature that I knew to be incorrect. For instance, it is commonly believed that Hawai'i's baby turtles making their way to the ocean are eaten by seabirds, an event that occurs regularly in other parts of the world but not in Hawai'i. Another assumption about sea turtles that I had is that turtles keep away sharks. Believing this, it was always comforting to see a turtle while swimming or surfing. Imagine my sur-

prise the first time I saw a dismembered turtle carcass float by with distinct shark bites in it. I've learned a lot while researching this project by reading and talking with people like George Balazs, who dedicates much of his life to understanding these special creatures, and also from growing up in Hawai'i and paying attention to what my Island friends and family have taught me. Lastly, I've drawn on my own experiences to compile this book, which I feel will answer most questions that people have about Hawaiian sea turtles and bring to light some new and interesting aspects of "turtlebilia" as well. Before going any further, you might want to familiarize yourself with some of these words: Aloha

benthic gravid pelagic pyrosomas turtlebilia

to love, show kindness, or bid good fortune. Often used as a greeting or farewell, the ocean floor possessing fertile eggs the open ocean luminescent floating invertebrates anything to do with turtles (A word I just made up.)

Most other scientific or Hawaiian words will be defined in the text. So, take a deep breath, dive in, and happy reading!

A bowl of soup at a party . . . that is my first memory of a green sea turtle. The year was 1967. I was five years old. After I finished the soup and dumplings, my uncle asked, "So, how's the honu?" "What's honu?" I answered. "Sea turtle. That was turtle soup!" He laughed. "Turtle soup? I ate turtle soup!" I thought of my pet turtle at home. Quickly I ran to the nearest cooler and guzzled down two sodas. Three years later, while combing the tide pools of Sandy Beach with my father, I noticed a dark shape moving through the water. Shark, I thought. "Honu," my dad said. "Haven't you ever seen a sea turtle?" I watched the turtle's head pop up above the water's surface from time to time. When a swell rose, I could see its shape gliding through the water. It seemed as though I was watching the world's rarest animal. I was ecstatic. No one within earshot was spared from my experience; my family, friends, and neighbors listened patiently to my tale. My third-grade teacher and classmates got the enhanced, adventurous version, with me riding on the turtle's back through a maze of sea caves. After all, I was an energetic kid with a vivid imagination. I couldn't let some other kid come up with a better show-and-tell story than mine.

My teacher smiled at me knowingly. "You know, turtles are good luck," she said. "You must be really lucky!" In the years that followed, my career as a wildlife artist and ranger brought me together with the honu on numerous occasions. By working with and living near honu on remote Hawaiian atolls, I got to observe many aspects of their lives—mating, egg laying, nest hatchings, even shark attacks. My real-life adventures made those yarns I told as a child seem boring. There are a lot more honu around today than there were when I was young. Laws protecting sea turtles have greatly aided their recovery; however, recent threats such as mysterious tumors, entanglement, beach development, and pollution continue to jeopardize the honu's future. Nowadays I listen to people who excitedly tell me about their own honu experiences. I smile and recall my third-grade teacher mentioning that turtles are good luck. I remember seeing my first honu and how my heart went sailing through the water with it. How could I not feel lucky?

/H

of

Hah^x

'Ea is the traditional Hawaiian name of the hawksbill sea turtle (Eretmochelys imbricata). The name may refer to the ancient practice of using this turtle's shell to treat thrush or other infections, called 'ea. In recent times the hawksbill is sometimes called honu 'ea; however, in the days of old, the words "honu" and "'ea" referred to two very different beings and were not interchanged or combined.

Prior to Western contact the only turtles known to Hawaiians were the indigenous turtles of the sea. The more commonly seen species likely had specific Hawaiian names; however, some of those names may have been lost or forgotten over time. Two ancient Hawaiian names that have survived into present day are honu and 'ea. "Honu" is the traditional Hawaiian name given to the species Chelonia mydas, or green sea turtle. In old Hawai'i the different kinds of sea turtles represented very different entities and were referred to by different names. Today, however, several or all turtle species are often grouped together, and it is now common for people to use "honu" in a general sense to mean "sea turtle" or simply "turtle." For example, if you were to ask a native what the word for turtle is, he or she might reply, "honu. " Within the past two centuries, several species of freshwater and land turtles have been introduced to Hawai'i. Again the word "honu" may be used in reference to these recent arrivals, as in honu kahiki (foreign turtle). 4-

Throughout the ages turtles have been symbols of good luck and long life. Many cultures hold these animals in high regard; some even revere them as gods. This is especially true in Hawai'i, where many Islanders worship sea turtles as family guardians, or 'aumakua. To these families the turtle is not only a protector but also the embodiment of their ancestors. In old Hawai'i members of the Honu clan did not eat the sea turtle, nor were any women allowed to partake of them. To an ali'i (chief) the meat of the honu was presented along with its head, which continued to "live" even after being detached from its body. This phenomenon was attributed to the honu's powerful life force. Hawaiians believed that by eating the honu, its life force would be passed on to them. When a honu was captured, very little of it was left unused. Soup or stew was made from its cartilage and flesh, which was rich and nutritious. Even the intestines or other loko (internal organs) were prepared and savored. Fishhooks, bark scrapers, and other tools were made from a turtle's bones and shell, and pliable leather from its skin. Sometimes a honu was presented as an offering to Kanaloa, God of the Sea. The honu is also one of the kino lau (physical lifeforms) that Kanaloa is believed to take when he is in need of an earthly body. Prominent in Hawaiian lore, mention of the honu dates back to the Kumulipo, or ancient creation chant. Countless stories of honu with supernatural powers have been passed down through generations, including the story of Kauila, a magical honu that lived along the black sand beach of Punalu'u on the Big Island of Hawai'i. Kauila had the power to turn herself into a young girl and back to a turtle at will. She did this so she could play with and S

watch over the children she loved. The people of Punalu'u adored Kauila as a friend and guardian of their children. Today the turtles of Punalu'u are still famous for being tame and friendly toward swimmers, and many say the presence of Kauila can still be felt there.

Turtles are an order of reptiles that are distinguished by an outer shell. This shell is actually part of the turtle's skeleton that grows around its body, protecting its organs and other soft body parts. Some kinds of turtles are even able to tuck their head and limbs into their shells to avoid danger; hence the familiar expression that turtles carry their houses on their backs. While most kinds of turtles live on land (tortoises) or in and around freshwater (aquatic turtles), one group has adapted to the ocean environment. These turtles, commonly known as sea

turtles, developed paddlelike flippers and a streamlined body shape. This body design is excellent for moving through water; however, it does not allow sea turtles to retract their appendages, and so gives them limited armored protection against predators. The ancestors of sea turtles were giant land turtles that roamed the earth during the time of dinosaurs. More than ninety million years ago, some of these turtles adapted to life in the sea. The prehistoric sea turtles outlasted the giant land turtles and dinosaurs and, through the ages, evolved into the sea turtles of today. BEAK

TOP (DORSAL) VIEW

EYE SCALES

BOTTOM (VENTRAL) VIEW

FOREFLIPPER

CARAPACE (shell)

MARGINAL SCUTES LATERAL SCUTES CENTRAL SCUTES HIND FLIPPER

TAIL

6»

PLASTRON (belly plate)

Like all reptiles, sea turtles must breathe air to live. Normally, they come to the surface to breathe every few minutes; however, under certain conditions, their specially adapted physiology and respiratory systems allow them to stay submerged for hours. Sea turtles have leathery skin that, in all species except the leatherback, is partially covered with scales. Their shells are covered with plated sections called scutes, beneath which is a network of underlying bone and cartilage. The upper part of the turtle's shell is called the carapace, and the lower section or belly plate is the plastron. The turtle's limbs, or flippers, are much larger and longer in front than in back. These powerful foreflippers propel the turtle through the water, while its rear flippers are used more like steering rudders. Most species have a claw, sometimes two, on each flipper. The claws are used by the males to grasp hold of the females during mating. Though they have no teeth, sea turtles use their sharp, hard beaks to get food. Their beaks, scales, and outer layer of their shells are made of a substance called keratin, which

The elongated claw on the foreflipper of a male green turtle. © Muiile

C.ostj

Salt secretions, or "tears," flow from the eye of a green turtle.