Hal Whitehead - The Cultural Lives of Whales and Dolphins

THE CULTURAL LIVES OF WHALES AND DOLPHINS

THE CULTURAL LIVES OF WHALES AND DOLPHINS

HAL WHITEHEAD AND LUKE RENDELL

The University of Chicago Press

Chicago and London

Hal Whitehead is a University Research Professor in the Department of Biology at Dalhousie University in Halifax, Nova Scotia. Supported by the Marine Alliance for Science and Technology, Luke Rendell is a lecturer in biology at the Sea Mammal Research Unit and the Centre for Social Learning and Cognitive Evolution of the University of St. Andrews, Scotland.

The University of Chicago Press, Chicago 60637

The University of Chicago Press, Ltd., London

2015 by The University of Chicago

All rights reserved. Published 2015.

Printed in the United States of America

24 23 22 21 20 19 18 17 16 15 1 2 3 4 5

ISBN-13: 978-0-226-89531-4 (cloth)

ISBN-13: 978-0-226-18742-6 (e-book)

DOI: 10.7208/chicago/ 9780226187426.001.0001

Library of Congress Cataloging-in-Publication Data

Whitehead, Hal, author.

The cultural lives of whales and dolphins / Hal Whitehead and Luke Rendell.

pages ; cm

Includes bibliographical references and index.

ISBN 978-0-226-89531-4 (cloth : alk. paper)

ISBN 0-226-89531-9 (cloth : alk. paper)

ISBN 978-0-226-18742-6 (e-book)

1. Whales. 2. Dolphins. 3. Social behavior in animals.

4. Animal communication. I. Rendell, Luke, 1973 author. II. Title.

QL737.C4W47 2015

599.5dc23

2014020610

This paper meets the requirements of ANSI / NISO Z39.481992 (Permanence of Paper).

Dedicated to the memory of

C HRIS R ENDELL and F RANKIE W HITEHEAD

CONTENTS

Ocean of Song

We love wilderness, the parts of the earth where humans have little impact. So much of the planet is eroded, polluted, and dominated by people. Well, not people directly. It is rarely the mere physical presence of large numbers of humans that degradesit is, rather, what we do, as well as our products, our methods of exploiting the land, the plants, and the animals, the effluents of our industries, and the things that we build. All these are the results of human culture, the body of knowledge, skills, customs, and materials that each generation inherits and builds on and that surround us every moment of our lives. We are born with the genetic template of Homo sapiens, but we cannot become fully human without what we learn from each other. Human culture accumulates, so the good can become very, very goodlike the routine treatment of medical conditions lethal not a century agoand the bad, such as our pollution of the earth and its atmosphere, can get worse. This feature of our societies is a large part of what makes humans unique. The effects of our cultures are very nearly omnipresent, affecting the entire earth. The one major part of our planets surface where humans and our cultures are least apparent is the deep ocean.

So we love to sail the deep ocean. Unless crossing a shipping lane, a fishing ground, or a garbage-strewn central-ocean gyre, we see few signs of humans outside our twelve-meter sailing boat. Out here, it would be easy to believe we have managed to escape the mess humanity has made of the earth. In reality, we have not. There are far fewer turtles and sharks and whales than even a hundred years ago, before humans learned such effective ways of killing them. The deep-ocean waters are more polluted and acidic than they used to be. But it feels like wilderness. We do not directly see the lack of ocean wildlifeor the pollutants.

Far out in the ocean, we have escaped the vast dominance of human cultural impact, although to make this escape we have to use the seafaring knowledge and technology that humans have built up over many generations. This accumulation began before 5,000 B.C. , when the earliest known depictions of sailing boats appeared (plate 1).the late Middle Ages sailing ships became some of the most technologically advanced elements of human culture, and human mobility took a great stride forward. The yachts we sail for our research, with their fiberglass hulls, stainless-steel fittings, and Dacron sails, are technological descendants of those ships (plate 2). They are products of a system of cumulative cultural evolution that allow humans to cross oceans reasonably reliably, a remarkable achievement for a terrestrial mammal.

As we sail, every half hour we listen to the ocean through a hydrophone, an underwater microphone towed behind our boat on a hundred-meter cable. We hear waves, and sometimes dolphins. Quite often there is the deep rumble of ships. We can hear the ships farther than we can see them, and their rumble signifies that this is not the wilderness that it appears.

Despite this, on recent voyages through the Sargasso Sea in the western North Atlantic, we heard another type of sound more often than the whistles of dolphins or the throb of ships. Not one sound, but an extraordinary range of sounds, high sweeping squeals, low swoops, barking, and ratchets. All are part of the song of the humpback whale. In February 2008 we heard humpbacks at 45 percent of our half-hourly hydrophone listening stations over two thousand kilometers of ocean between Bermuda and Antigua. As we will explain later, we think that humpback song is a form of nonhuman culture. A humpback whale learns the song from other humpback whales and passes it on. Some liken it to human music, others to the songs of birds; it has elements of both. Within the frequencies that we can hear on our hydrophone and over thousands of kilometers of ocean, the culture of the humpback whale dominates the acoustic environment of the ocean, as it has for millions of years. Human cultural supremacy over the surface of the earth is recent and not quite complete. If we could have listened at lower frequencies, below the limits of the human ear, we would have heard rumbles and groans of other whalesthe finback and the bluetheir songs competing in the lowest frequency bands with the recent sound of ships. Could these be other nonhuman cultures?

This book is about the culture of the whales and dolphins, known collectively as the cetaceans. What is it? Does it even exist? If it does, why? What might it mean? It is also about our evolving understanding of nonhuman societies and, through them, what it means to be human. We are carried by rafts of insights hard won from the oceans by scientists all over the world.

Culture Changes Everything

To biologists like us, culture is a flow of information moving from animal to animal. So an animal may eat a certain food because of preferences largely coded in its genes or because it learned from others that the food is good. An animal may also develop preferences through individual learning, for instance, working out that something is good to eat through its own experimentation. In fact, virtually all the information that moves around through cultural processes originates in this way. However, individual learning on its own does not involve information transfer between organisms and so cannot transform biology in the manner that cultural transmission does.

These processes can interact in different ways. A bird may have the genetically driven instinct to migrate but learn the route from others. Some behavior can be acquired either way. For instance the calls of cuckoos (and many other birds) can mostly develop without social inputs, whereas canaries, finches, and other birds in the oscine suborder learn at least some aspects of their song from others, so their song is a form of culture. Genetic determination and social learning are, however, fundamentally different processes. Tellingly, the cultural songs of the oscine birds are generally more complex, sometimes much more so, and more diverse than the genetically driven nonoscine calls.