Tuesday, November 23, 2004

Has Success Spoiled The Crow? by David Quammen

Has Success Spoiled The Crow?
The Puzzling Case File on the World's Smartest Bird
--borrowed from David Quammen's Natural Acts, sans permission.--
(found at http://home.alltel.net/sammurdock/cm/corviary/success.html)
Any person with no steady job and no children naturally finds time for a sizeable amount of utterly idle speculation. For instance, me--I've developed a theory about crows. It goes like this:
Crows are bored. They suffer from being too intelligent for their station in life. Respectable evolutionary success is simply not, for these brainy and complex birds, enough. They are dissatisfied with the narrow goals and horizons of that tired old Darwinian struggle. On the lookout for a new challenge. See them there, lined up conspiratorially along a fence rail or a high wire, shoulder to shoulder, alert, self-contained, missing nothing. Feeling discreetly thwarted. Waiting, like an ambitious understudy, for their break. Dolphins and whales and chimpanzees get all the fawning publicity, great fuss made over their near-human intelligence. But don't be fooled. Crows are not stupid. Far from it. They are merely underachievers. They are bored.
Most likely it runs in their genes, along with the black plumage and the talent for vocal mimicry. Crows belong to a remarkable family of birds known as the Corvidae, also including ravens, magpies, jackdaws, and jays, and the case file on this entire clan is so full of prodigious and quirky behavior that it cries out for interpretation not by an ornithologist but a psychiatrist. Or, failing that, some ignoramus with a supple theory. Computerized ecologist can give us those fancy equations depicting the whole course of a creature's life history in terms of energy allotment to hunger and motherly love, but they haven't yet programmed in a variable for boredom. No wonder the Corvidae dossier is still packed with unanswered questions.
At first glance, though, all is normal: crows and their corvid relatives seem to lead an exemplary birdlike existence. The home life is stable and protective. Monogamy is the rule, and most mated pairs stay together until death. Courtship is elaborate, even rather tender, with the male doing a good bit of bowing and dancing and jiving, not to mention supplying his intended with food; eventually he offers the first scrap of nesting material as a sly hint that they get on with it. While she incubates a clutch of four to six eggs, he continues to furnish the groceries, and stands watch nearby at night. Then for a month after hatching, both parents dote on the young. Despite strenuous care, mortality among fledglings is routinely high, sometimes as high as 70 percent, but all this crib death is counterbalanced by the longevity of the adults. Twenty-year-old crows are not unusual, and one raven in captivity survived to age twenty-nine. Anyway, corvids show no inclination toward breeding themselves up to huge numbers, filling the countryside with their kind (like the late passenger pigeon, or an infesting variety of insect) until conditions shift for the worse, and a vast population collapses. Instead, crows and their relatives reproduce at roughly the same stringent rate though periods of bounty or austerity, maintaining levels of population that are modest but consistent, and which can be supported throughout any foreseeable hard times. In this sense they are astute pessimists. One consequence of such modesty of demographic ambition is to leave them with excess time, and energy, not desperately required for survival.
The other thing they possess in excess is brain-power. They have the largest cerebral hemispheres, relative to body size, of any avian family. On various intelligence tests--to measure learning facility, clock-reading skills, the ability to count--they have made other birds look doltish. One British authority, Sylvia Bruce Wilmore, pronounces them "quicker on the uptake" than certain well-thought-of mammals like the cat and the monkey, and admits that her own tamed crow so effectively dominated the other animals in her household that this bird "would even pick up the spaniel's leash and lead him around the garden!" Wilmore also adds cryptically: "Scientists at the University of Mississippi have been successful in getting the cooperation of Crows." But she fails to make clear whether that was as test subjects, or on a consultative basis.
From other crow experts come the same sort of anecdote. Crows hiding food in all manner of unlikely spots and relying on their uncanny memories, like adepts at the game of Concentration, to find the caches again later. Crows using twenty-three distinct forms of call to communicate various sorts of information to each other. Crows in flight dropping clams and walnuts on the highway pavement, to break open the shells so the meats can be eaten. Then there's the one about the hooded crow, a species whose range includes Finland: "In this land Hoodies show great initiative during winter when men fish through holes in the ice. Fishermen leave baited lines in the water to catch fish and on their return they have found a Hoodie pulling in the line with its bill, and walking away from the hole, then putting down the line and walking back on it to stop it sliding, and pulling it again until [the crow] catches the fish on the end of the line." These birds are bright.
And probably--according to my theory--they are too bright for their own good. You know the pattern. Time on their hands. Under-employed and over-qualified. Large amounts of potential just lying fallow. Peck up a little corn, knock back a few grasshoppers, carry a beak-full of dead rabbit home for the kids, then fly over to sit on a fence rail with eight or ten cronies and watch some poor farmer sweat like a sow at the wheel of his tractor. An easy enough life, but is this it? Is this all?
I f you don't believe me just take my word for it: Crows are bored.
And so there arise, as recorded in the case file, these certain . . . no, symptoms is too strong. Call them, rather, patterns of gratuitous behavior.
For example, they play a lot.
Animal play is a reasonably common phenomenon, at least among certain mammals, especially in the young of those species. Play activities--by definition--are any that serve no immediate biological function, and which therefore do not directly improve the animal's prospects for survival and reproduction. The corvids, according to expert testimony, are irrepressibly playful. In fact, they show the most complex play known in birds. Ravens play toss with themselves in the air, dropping and catching again a small twig. They lie on their backs and juggle objects (in one recorded case, a rubber ball) between beak and feet. They jostle each other sociably in a version of "king of the mountain" with no real territorial stakes. Crows are equally frivolous. They play a brand of rugby, wherein one crow picks up a while pebble or a bit of shell and flies from tree to tree, taking a friendly bashing from its buddies until it drops the token. And they have a comedy-acrobatic routine: allowing themselves to tip backward dizzily from a wire perch, holding a loose grip so as to hang upside down, spreading out both wings, then daringly letting go with one foot; finally switching feet to let go with the other. Such shameless hot-dogging is usually performed for a small audience of other crows.
There is also an element of the practical jokester. Of the Indian house crow, Wilmore says: ". . . this Crow has a sense of humor, and revels in the discomfort caused by its playful tweaking at the tails of other birds, and at the ears of sleeping cows and dogs; it also pecks the toes of flying foxes as they hang sleeping in their roosts." This crow is a laff riot. Another of Wilmore's favorite species amuses itself, she says, by "dropping down on sleeping rabbits and rapping them over the skull or settling down on drowsy cattle and startling them." What we have here is actually a distinct subcategory of playfulness known, where I come from at least, as Cruisin' For A Bruisin'. It has been clinically linked to boredom.
Further evidence: Crows are known to indulge in sunbathing. "When sunning at fairly high intensity," says another British corvidist, "the bird usually positions itself sideways on to the sun and erects its feathers, especially those on head, belly, flanks, and rump." So the truth is out: Under those sleek ebony feathers, they are tan. And of course sunbathing (like ice-fishing, come to think of it) constitutes prima facie proof of a state of paralytic ennui.
But the final and most conclusive bit of data comes from a monograph by K. E. L. Simmons published in the Journal of Zoology, out of London. (Perhaps it's for deep reasons of national character that the British lead the world in the study of crows; in England, boredom has great cachet.) Simmon's paper is curiously entitled "Anting and the Problem of Self-Stimulation." Anting as used here is simply the verb (or to be more precise, participial) form of the insect. In ornithological parlance, it means that a bird--for reasons that remain mysterious--has taken to rubbing itself with mouthfuls of squashed ants. Simmons writes: "True anting consists of highly stereotyped movements whereby the birds apply ants to their feathers or expose their plumage to the ants." Besides direct application, done with the beak, there is also a variant called passive anting: The bird intentionally squats on a disturbed ant-hill, allowing (inviting) hundreds of ants to swarm over its body.
Altogether strange behavior, and especially notorious for it are the corvids. Crows avidly rub their bodies with squashed ants. They wallow amid busy ant colonies and let themselves become acrawl. They revel in formication.
Why? One theory is that the formic acid produced (as a defense chemical) by some ants is useful for conditioning feathers and ridding the birds of external parasites. But Simmons cites several other researchers who have independently reached a different conclusion. One of these scientists declared that the purpose of anting "is the stimulation and soothing of the body," and that the general effect "is similar to that gained by humanity from the use of external stimulants, soothing ointments, counter-irritants (including formic acid) and perhaps also smoking." Another compared anting to "the human habits of smoking and drug-taking" and maintained that "it has no biological purpose but is indulged in for its own sake, for the feeling of well-being and ecstasy it induces . . ."
You know the pattern. High intelligence, large promise. Early success without great effort. Then a certain loss of purposefulness. Manifestation of detachment and cruel humor. Boredom. Finally the dangerous spiral into drug abuse.
But maybe it's not too late for the corvids. Keep that in mind next time you run into a raven, or a magpie, or a crow. Look the bird in the eye. Consider its frustrations. Try to say something stimulating.