|
Something To Crow About
By Michele Solis
In the Company of Crows and Ravens
by John Marzluff and Tony Angell
Yale University Press, 2005
Noisy, plain, sulking on telephone lines, or loitering around trash cans, crows are unremarkable at best, and nuisances at worst. But when it comes to intelligence, these ordinary birds are exceptional. They live in complex societies, use tools, and have elaborate communication skills. They may even have culture.
For a wide-ranging portrayal of these birds and their corvid kin, turn to In the Company of Crows and Ravens by John Marzluff and Tony Angell.
Marzluff, a wildlife scientist at the University of Washington, and Angell, a writer and artist from Lopez Island, have produced a fascinating compendium of corvid history, research, anecdote, and musings about the birds that could pass as our avian doubles: "To a surprising extent, to know the crow is to know ourselves," they note. Marzluff and Angell also explore the ways that crows and humans have influenced each other over history, and propose an intricate cultural co-evolution between them. Throughout, the authors tirelessly peck, poke, and pry open our hearts and minds to win our admiration for these beguiling birds.
The book alights on corvid topics ranging from life-long mates, vocal dialects, play behavior (tug-of-war is a favorite), and funerals. It even includes how crows taste when sautéed in oil, garlic, and red pepper sauce (". . . tasty, a far cry from your everyday chicken . . ."). But amid all the exotica, the basics are not neglected. The book explains that crows and ravens are not two, but rather 43 different species belonging to the corvid genus, and living nearly all over the world in desert, arctic, rural, and urban environments.
This diversity is richly illustrated with the detailed black and white drawings by Angell which depict the birds strutting, mobbing, preening, cawing, sunning, and of course, hanging around a dumpster. The drawings are customized for nearby text, which lends a storybook feeling to the reading.
And, as in a storybook in which animals are cleverer than we know, the book brings to life the legendary corvid intelligence with tales of their tool use, memory, and deceptions. Brain-wise, corvids are more like "flying monkeys" than birds. Crows not only use tools, but they will create one if they need to. Better yet, they will borrow one from humans, as in the case of crows in Japan using cars to crack their walnuts: they position the nuts in front of the tires of cars stopped at intersections, then retrieve their nut meat once the lights have turned green and the cars have passed, crushing the shells. Corvid memories are vast, and crows banded by Marzluff and his team seem to remember them and the aversive experience, picking the scientists out of thousands of people on campus and "uttering a call that sounds like vocal disgust" as they flee. Corvids also cache surplus food for later use in numerous hiding places. Oddly, they often just pretend to cache food when with other birds, a deception implying some insight into the thoughts of fellow birds, and indicating higher cognitive abilities.
These behaviors are engrossing enough on their own, but the book goes one step further to focus on the relationship between corvid and human behavior. These birds, particularly crows, have followed us from forest to farm to city to suburbs, adapting to and exploiting the changes we have imposed upon the environment along the way. For example, city-dwelling crows do not share the nest defense tactics of their rural kin. In rural areas, crows become agitated when humans approach their nests, but because they are commonly shot at in these locales, they keep their distance, even when someone climbs the tree. City crows, however, are spared such harassment in their urban homes and are thus more tolerant of human proximity to their nests, yet bolder when a human climbs their tree, aggressively defending their nests with a "crow riot."
The authors are preoccupied with whether such adaptations constitute cultural changes, and propose a cultural co-evolution between corvids and humans by which they influence not only the behavior, but the culture of the other species. In the book, culture refers to behaviors passed on by social learning, and for humans, it is easier to recognize corvid influences on our culture, with their many appearances in our mythology, cave art, poetry, and idiomatic expression ("to eat crow," "as the crow flies," "crow bait"). For crows and ravens, it is harder to say whether they even have culture for humans to change, since, as the authors concede, their new behaviors could arise either through cultural transmission or through individual trial-and-error learning by enterprising birds.
Cultural co-evolution or not, the human impact on crows and ravens is far greater than what these birds have been able to visit upon humans. Crows thrive in urban areas, due to concentrated and reliable sources of trash, their main food source, and the lack of natural predators. Even so, the uniformity of the urban landscape threatens species diversity: "We will have changed their course of evolution in a homogenizing way– forming a blended, generic, all-purpose crow." This decrease in species diversity is also taken up in the story of the Hawaiian crow, now extinct in the wild. Through these stories, the book teaches evolutionary phenomena such as natural selection, speciation, and the founder effect in an easy-to-follow style. Using the commonplace crow to illustrate these concepts gives a fresh and immediate quality to evolutionary processes, which sometimes get a bit musty in the usual fossil-laden explanations.
Although research is at its foundation, this book is an all-inclusive almanac that contains anecdote and speculation alongside the data. This gives a friendly, conversational tone to the book, but it too often blurs the line between data and conjecture. Yet, the assortment of ideas stimulates specialist and layperson alike, and the book closes by encouraging us to "…keep watching and wondering." Readers are left with a new appreciation for these birds, and an ability to pick out bits of the remarkable in the ordinary.
|
|
|