Mind of the Raven: Investigations and Adventures With Wolf-Birds Read online

  Mind of the Raven

  INVESTIGATIONS AND ADVENTURES WITH WOLF-BIRDS

  Bernd Heinrich

  To Raven characters I have known,

  especially to Matt, Munster, Goliath,

  Whitefeather, Fuzz, Houdi, and Hook

  CONTENTS

  Acknowledgments

  Preface

  1 Becoming a Raven Father

  2 A Field Experiment

  3 Ravens in the Family

  4 Ringing Necks for Baby Food

  5 Education

  6 The Fate of Young Ravens

  7 Settling in a Home Territory

  8 To Catch and Track a Raven

  9 Partnerships and Social Webs

  10 Pairs as Cooperative Teams and Sharing

  11 Hunting and Foraging

  12 Adoption

  13 Sensory Discrimination

  14 Individual Recognition

  15 Dangerous Neighbors

  16 Vocal Communication

  17 Prestige Among Ravens

  18 Ravens’ Fears

  19 Ravens and Wolves in Yellowstone

  20 From Wolf-Birds to Human-Birds

  21 Tulugaq

  22 Caching, Cache-Raiding, and Deception

  23 Morality, Tolerance, and Cooperation

  24 Play by Ravens

  25 Deliberate Acts?

  26 Testing Raven Intelligence

  27 Brains and Brain Volume

  28 Are Ravens Conscious and Emotional?

  29 Back to the Wild

  Afterword

  Notes and References

  Searchable Terms

  About the Author

  Other Books by Bernd Heinrich

  Copyright

  About the Publisher

  Acknowledgments

  This book grew largely out of the generosity of people who have shared their raven experiences and news, offered help and encouragement, and even aided in the field studies. All have helped to greatly enlarge our understanding and appreciation of this magnificent bird. This book is, then, a tribute to the generous input of: Aaron Adams, Bill Adams, Andy Adderman, Phil Angle, Amy Arnett, David Barash, Mark Bekoff, Cindy Bellinger, Trond Berg, Peter Bergstrom, Bill Boarman, Diane Boyd, Jim Brandenberg, George Brady, Cathy Bricker, Neil Buckley, Thomas Bugnyar, Eric Busch, Duane Callahan, David Campbell, Linda Campbell, Geoff Carroll, Rachel Carter, Doug Chadwick, William Chester, Gary Clowers, Craig Comstock, Eileen Connor, Bob Crabtree, Dorothy Crumb, Moria Daley, Mark Damon, Josina Davis, Richard Donley, Bill Drury, Micha Dudek, Randy Durand, Steve Emslie, Adam Farrington, Anell Farris, Gerald Fitz, Lori Friedman, Herbert Fuchs, Jean Craighead George, Ted Gaine, Ron Gerrish, Terry Goodhue, Donald Griffin, Thomas Grünkorn, Tim Hall, Forrest Hammond, Hilmar Hansen, Fred Harrington, Rolf Hauri, Stuart Heinrich, Kay Hensler, Monika Hilker, Carsten Hinnerichs, Garth Holman, Richard Hoppe, Stuart and Mary Houston, Beat Huber, Wendy Howe, Jim Hunter, Inooqi Irguittuq, Fran James, Delia Kaye, Paula Kelly, Bill Kilpatrick, Don Kilpela, Ted Knight, Catherine Koehler, Kurt Kotrchal, Bob Landis, Rachel Lawler, Bob Lawrence, Gale Lawrence, Don Lego, Ted Levin, Matt Libby, David Lidstone, Scott Lindsay, Volker Looft, Barry Lopez, Valerie Lownes, Marcy Mahr, Mary Majka, Marvis Mark, Hans-Dieter Martens, John and Colleen Marzluff, Declan McCabe, Sarah McCracken, John McDonald, Terry McEneaney, Lorin McKay, David Mech, Brad Meiklejohn, Larry Melcher, Randolf Menzel, Gail Mihocko, Michael Miller, John Moran, Klaus Morkramer, Kim Most, Dick Nelson, John and Bob Nicholson, Janet Nook, John and Thomas Nutaraviaq, Abe Okpik, Kristian Omland, Nikita Orsyanikov, Linda Osborne, Tim Osborne, Jane Packard, Mike Palmer, Jack Parriott, Ray Paunovich, Doug Peacock, Hill Penfold, Lyn Peplinski, John Pepper, Mike Peterson, Rolf Peterson, Diane Pickard, Raymond Pierotti, Noah Piugaattuq, Andrea Ramsden, Natalie Rapp, Derek Ratcliffe, Jörg Reimers, Barbara Reif, Cindy Riegel, John Robertson, Ethan Rochmis, Michael Romero, Emanuel Rosen, Barry Rothfuss, Lorenzo Russo, Jenny Ryan, Bob Sam, Akaka Sataa, John Sawyer, George Schaller, Joseph Schall, Doug Schamel, Kristin Schaumburg, Charlie Sewall, Paul Sherman, Lorrell Shields, Phil Silverson, Rick Sinnett, Doug Smith, Roger Smith, John Snell, Ron Spiegel, Dan Stahler, Joanne and Neil Stinneford, Theo Stein, Carl Striedieck, Guy Stevens, Todd Sweberg, Jan Tinbergen, William Townsend, Jeff Turner, Charlie Uttak, Bill Valleau, Johanna Vienneau, Tinker Vitelli, Julia Voge, Wolfe Wagman, Dieter Wallenschläger, Chris Walsh, Mike and Ina Wesno, Steve Wheeler, John Williams, Mary Willson, Lesly Woodroffe, August Wright, Brent Ybarrondo, and Ann Yezerski, and all of those whose names now elude me.

  It is impossible for me to single out each for their unique contributions. However, I give thanks to Ted Knight, Delia Kaye, Kristin Schaumburg, and Eileen Connor for freely volunteering months of dedicated labor on an often frustrating radio-tracking project. John and Colleen Marzluff invested three years of hard work, and many great ideas, that were invaluable in securing the recruitment hypothesis. I thank my agent, Sandra Dijkstra, and my editor, Diane Reverand, whose instincts on what constitutes a book have been an invaluable guide. My wife, Rachel Smolker, who gracefully endured my sometimes prolonged “absences” to be mentally if not physically with the ravens. Rachel’s fine biological insights and keen editorial comments helped me say what I wanted to convey. Kimberly Layfield transformed my often inscrutable raven-scratch handwriting to type, and always did it with good cheer, and with speed and efficiency. The various institutional, state, and federal agencies expeditiously eased the permit process, and I thank them for thereby acknowledging the value of our gaining intimate contact with our fellow creatures.

  My last batch of youngsters, including Red, Blue, Yellow, White, Orange, Green, and Eliot.

  Preface

  “It was better, I decided, for the emissaries returning from the wilderness, even if they were merely descending from a stepladder, to record their marvel not to define its meaning. In that way it would go echoing on through the minds of men, each grasping at that beyond out of which the miracles emerge, and which once defined, ceases to satisfy the human need for symbols.”

  LOREN EISELEY,

  “The Judgement of the Birds,” The Immense Journey, 1946

  I HAVE LIVED AND BREATHED RAVENS since a date I will remember: October 29, 1984. On the afternoon of that day, I was drawn to the commotion of a group of ravens at a moose carcass. If even I could be attracted to a carcass from over a mile away, then ravens should be ever more so. The birds seemed to be advertising their find, which meant they would have to share it. I was deeply puzzled by the mystery posed by this phenomenon, and I wrote a book about my efforts to understand it. I was then not aware that the study, and the subsequent ones covered in this book, had been presaged more than two years earlier in a journal entry of mine from February 21, 1981, that described a dream from the night before: “I was walking in a dark and very mysterious forest and heard the croaking of ravens, one of the most awesome sounds I know. The ravens’ calls told me that their nest was near. The ravens’ calls were full of promise. I felt I was close to something new and exciting, and would find it.” Then I awoke. I had always wanted to find the nest of a raven. Was that the focus of its intimate life?

  Why would anyone dream about ravens? The common raven, Corvus corax, is the world’s largest crow, usually exceeding goshawks and red-tailed hawks in size. (I will here not use the ornithological convention of capitalizing bird names, adhering to literary usage instead.) It was extremely rare here in northeastern North America fifty years ago, whereas the smaller American crow, Corvus brachyrhynchos, which resembles it superficially, was and still is extremely abundant. Cornell ornithologist
and bird artist George Miksch Sutton wrote in 1936 that the raven is “wary and solitary in nature.” He described it as a bird of the wilderness that few people ever saw, and like most people who know it, he singled it out for being special.

  All animals solve the same age-old problems relating to food, partnerships, sex, shelter, home, and caring for their young. Yet ravens have throughout history commonly been singled out to be most like man. Why? What is special about ravens that invites such a comparison?

  Humans usually have considered themselves to be different and apart from other animals. Perhaps, as lion researcher Craig Packer points out in his book Into Africa, that is because “we make it all up as we go along,” whereas an ant has “every small instruction laid out in advance.” Ravens, like humans and unlike perhaps most other birds, probably do not have instructions to all of life’s problems laid out in advance, or they would not likely have been considered highly intelligent, and mythologized as creators, destroyers, prophets, playful clowns, and tricksters. I have often been startled by their enigmatic and seemingly contradictory responses. But the poetry of biology resides hidden in opposing tensions, and the often arduous fun comes from trying to reveal it.

  To begin to see how the raven’s mind might be organized requires finding the focal points of its natural history, necessitating an openness to all the input of information one can muster. Since I wrote Ravens in Winter, I have intensified and greatly enlarged my original study. I have tried to see ravens from as many perspectives as possible that might reflect not only on their adaptive responses but also on the motivation of those responses. Hundreds of people have shared with me their experiences of seeing ravens’ behavior. They have been like extra eyes, probing where and when I could not reach. I have tried to sift carefully through these reports, but I’m able to offer here only a small minority that were appropriate for the context. I have tried to keep in mind that anecdotes can easily become interpretations, and that facts expand in minds when they are not opposed by knowledge. On the other hand, to reject all anecdotes is also to reject facts. With ravens, the line between interpretation and fact is commonly a thin one, but as Mark Pavelka, who studied ravens for the United States Fish and Wildlife Service, said, “With other animals you can usually throw out 90 percent of the stories you hear about them as exaggerations. With ravens, it’s the opposite. No matter how strange or amazing the story, chances are pretty good that at least some raven somewhere actually did that.” That is because ravens are individuals. Ants aren’t.

  It may be impossible to prove in a literal or absolute sense that any one particular animal has or does not have emotions, consciousness, or capacity for insight. These subjective, individual, and hard-to-define qualities of mind are found in separate independent evolutionary lines, with the highest end-points reached in some species of primates, cetaceans, and perhaps corvids and parrots. Trying to pin any of the many aspects of mind down to one particular amount in any one particular species, however, is like trying to specify the exact moment in a continuum of time when a child can or could talk. She is not talking when she makes gurgling sounds at the age of a few weeks, but she is doing so later when she says, “Mommy, please read me the story about the hungry caterpillar one more time.” Some of the varied vocalizations she makes in between the first sounds and the first sentence seem arbitrary, because they are. So it is with all aspects of mind, only we cannot measure them as precisely as we can sounds. And some, like the smell of a rose or the feel of a spring day, no matter how objectively and concretely they can be proven to affect behavior, will forever remain private.

  In the last several decades, there has been a blossoming in our awareness of animal minds, despite the large methodological problems of investigating them. Studies have shown many often unpreposessing animals to have amazing sensory and mental (probably unconcious) powers that were unsuspected, and that seem almost beyond belief. Many rival our own much-vaunted powers. Accounts of these amazing capabilities fill textbooks of animal behavior, and they startle and surprise our collective imagination. I know I have been, as are most students of biology, mesmerized by them. To mention only a tiny few almost at random out of the myriad to choose from, I’ve marveled at Harvard and Rockefeller Universities’ Donald Griffin’s discovery of how bats can detect and intercept flying moths in total darkness, and Ken Roeder’s findings of moths’ reflexes that foil bats. I’ve been awed by Karl von Frisch’s elucidation of how bees can perceive and learn to seek food associated with specific scents, colors, and geometrical patterns, and how they communicate to hivemates the distance and direction of food and/or potential home sites for departing swarms. I’ve admired Cornell’s Tom Seely’s extension of this work, showing the hive’s complex decision-making process, which proceeds seamlessly yet without insight, thinking, and intelligence as we normally define them for ourselves. In contrast, it is therefore all the more intriguing that the detailed studies by Dorothy Cheney and Robert Seyforth of wild vervet monkeys in Africa revealed that some of these animals’ calls contain semantic meanings, much like our words do, and the animals apparently know what some of their utterances mean, because they sometimes use them to deceive others for their own advantage. The work of Wolfgang Köhler in Germany, Frans de Waal at Emory University, Jane Goodall in Tanzania, and others has shown that some apes are also capable of self-recognition and deception of others. I was thrilled by Katie and Roger Payne’s discovery that humpback whales have elaborate, often hour-long songs whose precise sequence of sounds changes seasonally over the ocean basin, with all individual whales singing a similar song in any one year in either the Atlantic or the Pacific Ocean. I was surprised by the discovery that some dolphins swim around carrying sponges with them, probably to use as a foraging tool. Birds are just as amazing. Even pigeons, as Richard Herrenstein of Harvard proved, can recognize “trees” as a category in photographs, and can even differentiate one artist’s paintings from another’s. Gustav Kramer in Germany made startling discoveries through clever experiments showing that starlings (like honeybees also) use the sun as a compass to tell them the direction. But the sun is not a stationary beacon. It moves 15 degrees per hour, and the animals compensate, calculate in this movement, as it moves daily across the sky, by consulting an internal clock. He showed that warblers migrate at night, navigating by using the north star as a beacon; and through elegant experiments that will forever be classic in biology, the father and son team of John and Stephen Emlen built on this work to decipher the intricate combination of innate and learned components of the amazing starorientation behavior in indigo buntings. A variety of birds and other animals can use the earth’s magnetic fields for orientation. Birds routinely navigate to and from pinpoints on the globe separated by continents, presumably using largely innate, fairly inflexible navigation scripts. But abstract concept formation is not precluded. Just recently, Irene Pepperberg of University of Arizona, Tucson, has shown us through her patient and detailed work that even a parrot may learn to converse with a human, using a vocabulary of about seventy words. Only a year ago, Gavin Hunt of New Zealand revealed how an Australian crow makes two kinds of tools. In all these amazing studies, there is first the sheer surprise and the wonder of what the animal can do. There is then the question of meaning.

  Whatever else the behavior might be, it is a product of sensors and the animal’s mind. The primary value of the discoveries, however, is not that they might prove any particular of a variety of abstractions such as “innateness,” “consciousness,” “insight,” or “intelligence,” or whatever label anyone may try to give them. They are all manifestations of mind, but their marvelousness is independent of the specific microanatomical complexity of neural wiring that allows them to be.

  I had my first tame ravens—two of them in my apartment in Westwood—while I was still a graduate student at UCLA in the late 1960s. I would have liked to study them then, had I seen a problem to study. I didn’t see any, but in any case, we graduate students were per
haps jokingly advised not to study an animal smarter than ourselves. I worked first with protozoa, in whose simplicity I saw many problems. I choose next to concentrate on a caterpillar, only gradually working my way up to moths. For my first project, I tried to figure out how the large caterpillars of the moth, Manduca sexta, which gardeners routinely pick off of their tomato or tobacco plants, “solved” a simple problem: how to consume a huge leaf entirely while it was attached to the plant and the catapillar to it, and regardless of leaf shape. How could an animal do the equivalent of hanging on at the tip of a branch in the top of a tree and eat the branch too? The way the caterpillars did it looked like they planned ahead, but they didn’t. Experiments showed that blind and simple programmed responses explained their seemingly purposive actions quite nicely. That work later led me to look at behavior internally. I eavesdropped on neural messages that underlie rhythmic stereotyped behavior that was externally visible (flight) or invisible (shivering) in bumblebees. In all of this research, I felt, and still feel, in agreement with most other researchers, that insects’ behavior was largely prewired. It was physiology. Bumblebees’ foraging in the field showed sophisticated learning, blurring the physiology I felt comfortable with into what could more appropriately be called behavior. Birds seemed behaviorally extremely interesting, but I felt that all their overt behavior that could be known already was, and all that was internal never could be. How wrong I was on both counts!