Tuesday, March 1, 2011

Ravens in Winter

Ravens in Winter 
In 1984 field biologist Bernd Heinrich posed an interesting puzzle:  Why was it that the Ravens around his retreat in Maine seemed to be sharing food, even the harshest periods of winter, with unrelated birds?  Ravens (Corvus Corax) are  more solitary creatures than their urban cousins the Crows.  Their uncharacteristically communal behavior struck Heinrich as "left-wing", and with a scientists' obsessive curiosity he set out to discover why.  Over the course of four years, spending his winter vacations in the frigid Maine woods (while his colleagues "tend to spend their sabbatical years in distant, exotic lands"), hauling carcasses up the mountain to use as bait, spending weeks in a small shack in sub-zero conditions, where he can nothing but observe all day long, and where any other movement or activity jeopardizes the experiment, he gradually gathered the observations that would help him solve his problem.  Along the way, he became interested in the remarkable birds of the corvid family -- how intelligent, truly, are crows and ravens?  Do they play?  How complex are the social relationships, despite the Raven's solitary reputation?

Ravens in Winter attempts to answer these questions, or at least to look objectively at the information available.  Chapters detailing Heinrich's dogged perusal of ravens alternate with chapters that more broadly review the literature of what is known about raven's and their cousins.  

Heinrich comes to the question of Raven intelligence with an admirably scientific skepticism:

...[D]espite the overwhelming force of consensus, there is surprisingly little objective evidence that can be used to compare the ravens' intelligence vs. that of other corvid birds.  Indeed, a review of the literature convinces me that no proof of the raven's singular intelligence has yet been published.  Instead, many of the anecdotes purporting to show this are significant only if is taken for granted at the outset.

This circular nature of the definition of "intelligence" is a problem of critical importance to ethnology -- and to other disciplines as well .  In sociology debates over intelligence tests have raged for decades -- how do we measure intelligence, and is there any way to do that independent of our own cultural biases?  In computer science, it arises when systems seem to exhibit behavior which, in humans, we would consider intelligent -- a chess playing program, for instance.  Is this really intelligence, or simply a mechanical imitation of intelligence?  And if it's not "real" intelligence, what is the missing element that makes it incomplete?  

Since Descartes, who considered animals, to be mere automations, devoid of the spark of soul or consciousness he believed was the  mark human intelligence, there are many who make the same claim about animals -- that the things they do are not real thought or intelligence.

Alan Turing, in a paper way back in 1950 (Computer Machinery and Intelligence) offered a methodological test for his field, to cut through all the philosophical debate:  he proposed a game in which a subject converses, via keyboard, with an several unseen partners.    If the subject cannot reliably tell humans from machines -- then the machines can be said to have passed.  In other words, if it walks like a duck and quacks like a duck .... If you can't tell a difference between the behavior of a machine and the behavior we consider intelligent in humans, then for all practical purposes there is no difference.  

As powerful as the Turing test is, as a thought experiment, it seems to rest on a number of assumptions that have never really been tested.   Since our definition of intelligence is based on ourselves, it is natural to assume that something else that is intelligent will behave in similar ways.  But that isn't necessarily true.  The science fiction editor John W. Campbell used to tell his writers, "Write me a creature that things as well as a man, but not like a man."  Would a computer, the product of an very different process of development than that which created us, embodied in different mediums and related to the world in very different ways, manifest intelligence in a very different form.  In other words, could it thinks as well as us, but not like us?
And could Ravens and Crows -- the product of an entirely different evolutionary line than us (we don't share a common ancestor since well before the Age of Dinosaurs), with a different brain structure and a orientation on the world (they fly -- their natural element is three dimensional, and their sensory apparatus is very different  than our own), manifest intelligence in a way we might not immediately recognize?

Sociologists love to argue about IQ tests, and whether they can really be fair when the cultural backgrounds of the test designers and the subjects are very far apart.  With animals, the gulf is even wider.  For instance, we tend to put a lot of stock in the idea of the "mirror test" -- certain animals can recognize themselves in a mirror, which implies they have a sense of self, a subjective identity.  However, the mirror test is deeply rooted in our visual means of apprehending the world.  A number of birds -- who are also visually oriented creatures -- including Macaws, parrots and corvids  have been reported to pass the mirror test, as can many primates.  But dogs cannot.  And yet dogs can clearly recognize many individuals, humans and canine, by scent.  If the mirror reflected scent, instead of light, I suspect that all dogs would be able to recognize themselves and almost no primates would.

Ravens in Winter is a fascinating portrayal of the world of ravens, their relationships and their behavior.  But it is also a wonderful portrait of how science really works in the field.  Heinrich takes us from his initial observations, which sparked curiosity, framing a hypothesis, designing experiments (which often involved hauling large carcasses up into the mountains to attract the ravens), gathering observations and evidence, discarding hypotheses, creating new ones, more observations -- and so on until finally the data began to make sense and a valid theory emerged.  It is one of the best descriptions I have read of the scientific method in action.  

Ravens in Winter is a must read book for students of animal behavior -- and or corvids in particular.  But it is also a book for all lovers of science and nature.

Related Post at Birdland West
Dog Days, Raven Nights






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