From the issue dated October 1, 1999
A Naturalist in Vermont Shinnies Up Trees to Look Inside the Raven's Mind
Bernd Heinrich says the largest members of the crow family have an intelligence that goes beyond their genes
By PETER MONAGHAN
Burlington, Vt.
When ravens aren't flying upside down, cheekily tweaking the tails of wolves, or sliding down snow banks, they may be ganging up on eagles or pecking out the eyes of mud-bogged bison.
For ravens, voracious carnivores, those apparently make quite tasty treats.
The sleek, jet-black common raven, Corvus corax, is a flying, scavenging, gamboling, and killing machine that also, says Bernd Heinrich, "is expressive, communicates emotions and expectations, and acts as though it understands you."
To fathom the vagaries of this curious corvid, Mr. Heinrich, a professor of biology at the University of Vermont, would seem to be the ideal man. Like any good biologist, he is prepared to stalk his prey through rain, hail, sleet, and snow, for days at a time if necessary. But not every biologist has Mr. Heinrich's capabilities.
How many, nearing 60, could shinny up trees with only bare hands and climbing spurs? And in the dark, sub-zero?
That's Mr. Heinrich, by general acclaim the doyen of ravenologists.
Mr. Heinrich has no doubt why the raven, though still not well understood, compels so many birders: "Ravens have throughout history commonly been singled out to be most like man."
So he writes in Mind of the Raven: Investigations and Adventures With Wolf-Birds (HarperCollins Publishers), his summation of all he has learned about the largest member of the crow family.
Their special kinship to humans, he says, is their intelligence.
That remains a controversial claim. Despite decades of research, scientists still differ about whether any animals can think independently, outside the twin channels of genetic patterning and learned behavior.
Ravens, which grow to three times the size of crows, are more graceful, powerful, and reclusive. Found in much of North America and in northern climes worldwide, they are enormously resourceful. They may, for example, work in teams to force hawks to earth and kill them. They may mimic radio static, motorcycles, mining explosions, and human speech.
Little surprise, then, that the birds have been mythologized as "creators, destroyers, prophets, playful clowns, and tricksters," Mr. Heinrich notes.
At his home in the woods outside Burlington, one can see why friends and colleagues liken Mr. Heinrich to a raven – his angular face, piercing eyes, body as tough and wiry as a college half-miler's.
A closer resemblance, however, can be detected in his approach to research. Ravens, though extremely inquisitive, also can be skittish to the point of fearing even a mouse or a moth. Mr. Heinrich doggedly pursues any and every question of raven life, but in exploring the notion that ravens are capable of insight, or intelligence, is very cautious to distinguish between evidence and anecdote.
When he began his study of ravens in earnest, 20 years ago, he knew that he would not be able to depend solely on individual birds in the wild, because they range up to 100 square miles a day. So, he began raising as many as 25 ravens at a time. Collecting them as hatchlings, high in trees, he then studied them as captives, first in a huge aviary on property he owns in western Maine, and more recently in a smaller one at his home here.
Raising ravens is hard work. You have to feed them hourly with copious amounts of mice, grubs, woodchucks, chipmunks – in fact, any available meat, which often means road kill.
As he lugs a cut of frozen calf from his garage to his birds, Mr. Heinrich explains that he has wanted to explore such questions as why it is that ravens, though territorial and competitors for food, call other ravens, even strangers, to fresh kills. For that research, described in Ravens in Winter (Summit Books, 1989), he hefted frozen calf and goat carcasses through deep Maine snow and discovered that ravens recruit each other from loose confederations that are, in effect, "traveling information centers."
All his studies led him to conclude that "the birds' world is infinitely more complex than had been previously assumed."
What is one to make, for example, of the fact that ravens often accompany dangerous carnivores such as bears, as well as human hunters, on hunts? He calls ravens "wolf-birds" because they have long been known to be present when wolves kill. Most tantalizing are suggestions from hunters, particularly in Inuit territory, that ravens lead wolves and other carnivores to prey, even dipping their wings to indicate where it is, an ability Mr. Heinrich only tentatively credits.
But is that intelligence?
In 1990, Mr. Heinrich performed an experiment, now renowned among scientists studying animal cognition, to see if ravens were capable of ingenuity. He set them a task beyond the reach of both innate and learned responses – a chore that could not have evolved in the wild, or be learned by trial and error.
He dangled meat on a string from a perch to see whether his captive ravens would figure out how to pull the string up, step on it, pull it up some more, and so forth until attaining their prize.
Some did. So ravens could manipulate mental images to solve problems.
"The basic assumption has been that in animals, everything is totally unconscious; they're just a lot of automata," says Mr. Heinrich. Atypical rather than typical behaviors make the opposite case because "if only one or two do something, then it can't be hard-wired. So maybe they have consciousness."
His work has won praise from leading cognitive ethologists – scientists of animal thinking – including Donald R. Griffin, an associate at the Museum of Comparative Zoology at Harvard University, and the author of Animal Minds (University of Chicago Press, 1992), and James L. Gould, a professor of ecology and evolutionary biology at Princeton University, and author with Carol Grant Gould of The Animal Mind (W.H. Freeman & Company, 1994).
Mr. Heinrich's string experiment, says Mr. Gould, was "an outstanding example of doing a very difficult, time-consuming experiment in which you see from first to last how an animal forms a plan and executes it." The test should "open people's eyes to the ability of animals to do that," he says, because Mr. Heinrich isolated his research animals from birth.
Alas, Mr. Gould adds, there are "non-believers." Reviewers of Mr. Heinrich's work have complained of an "incredible leap of faith" and said that the dichotomy he makes between learning and genetic programming "is 20 years out of date." Responding in his new book, Mr. Heinrich writes: "There is no dichotomy. But I had tried to create one. That was the point of the experiment."
In academic science, however, an experiment like the string test may be problematic. Mr. Heinrich has at times had difficulty getting his findings published in some academic journals. Atypical behaviors – the ones that suggest animal intelligence, rather than instinct – don't lend themselves to the scientific method's call for repeatability and testability.
Raising his voice to be heard above the din of cawing birds, he says: "There's no way I could get a sense of their reactions, of their sense of the world, except in the very basest terms, if I only had them in a cage and looked at them under very controlled conditions."
If Mr. Heinrich could tolerate being penned up himself, he'd still be a cell physiologist. That's how he started his academic career. He became a biologist and naturalist because it permitted him to get out into the elements.
In 1994, for example, he and his pet raven, Jack, spent a year in a cabin he had built on 300 forested acres in western Maine, near where he grew up from age 10. He had purchased the land in 1977, while a young faculty member at the University of California at Berkeley.
The result was A Year in the Maine Woods (Perseus Books, 1994). Its sequel was The Trees in My Forest (HarperCollins Publishers, 1997) – a forest he called "my intimate companion." Colleagues said the books confirmed what they already knew: "Virtually everything out there, whether it's a leaf, an insect, a bird, a mammal, a broken twig, he can identify, and what had gone on in the preceding day or series of days that led to that sign in the field," says John M. Marzluff, who worked as a postdoctoral researcher with Mr. Heinrich for three years, and is now an assistant professor of wildlife science at the University of Washington. "He's by far the best naturalist I've ever been with in the field, and I've been with some good ones. But, man, he is outstanding."
Mr. Heinrich had already established his scientific credentials with books about insect biology, including Bumblebee Economics (Harvard University Press, 1979), which was nominated for the National Book Award. In 1998, he won the New England Book Award for his body of work.
Reviewing Mind of the Raven in The New York Times Book Review, the nature writer David Quammen was much taken with Mr. Heinrich's "formidable scientific rigor." Still, he noted that the book is "disorderly," perhaps "too directly derived from field notes and daily journal entries of the working scientist."
Mr. Heinrich, who likes to illustrate his books with line drawings, says the magic of ravens is in those details. But he does not dispute that he's not much of a publicist.
Standing in his front yard, snapping off poppy pods to shake out a meager snack of seeds, he shyly explains why, reclusive like his bird-mates, he has not been on the usual book tour: "I like to write 'em, I don't like to sell 'em."
Mr. Heinrich is a spartan biologist. He built his Maine cabin – in which, until recently, he spent half of each year – with ax-felled logs that he lugged from the woods with oxen. No electricity, phone, or running water – but it has a sweat lodge.
Mr. Marzluff says that when it comes to pursuing research, Mr. Heinrich can be "all-consumed" to the point of endangering his health. He has often sat in a bird blind, in the branches of a tree, for days on end, watching ravens through a crack, as winter snowmelt drips on his face.
The tree-climbing, it turns out, is nothing compared with another enviable research tool: He can run like the dickens.
In the late 1970s, the well-known Harvard sociobiologist, Edward O. Wilson, who has also lavishly praised Mr. Heinrich's research, encouraged him to take up competitive running. Mr. Heinrich quickly set four United States "ultradistance" records. In 1983, he covered just under 157 miles in a single, 24-hour run. The next year, he ran 100 miles in 12 hours, 27 minutes, bettering the record by a full hour.
After a hiatus to concentrate more on his research, he has just started preparing to run marathons and 50-milers again – "not too many." He turns 60 in April, and says, "I'll see if I'm in the range of records."
No 24-hour runs?
"I'm thinking about it."
In a sense, he began running early in his life. In Germany after World War II, when he was 5, his family fled the advancing Soviet Army and retreating S.S. troops, and took to foraging in the forests. For six years, to survive, they scratched up roots and herbs here, or caught and cooked a bird or mouse there.
His closest childhood companion was a crow he raised on worms and caterpillars.
He first lived with ravens when he adopted two as pets in his Westwood, Cal., apartment while he was a graduate student at the University of California at Los Angeles, in the late 1960s.
He still can scrounge – for road kill, like many a field biologist, or for rodents, like a woodsman of old.
So ... how do mice taste?
Like chicken?
"They taste like shit," he deadpans.
No, he admits, "they're like anything, if you know how to prepare them" – breaded and fried like chicken nuggets.
"I'm getting much more finicky in my old age," Mr. Heinrich flatly intones. He has pulled his research operations back to a comfortable ranch home here, which he shares with his wife, Rachel Smolker, a dolphin researcher, and their two children, one freshly hatched this summer.
Now he has alternatives to eating fresh road kill: "I can buy a regular steak. I'm spoiled."
Copyright © 1999 by The Chronicle of Higher Education
