Monday, June 04, 2007
In the Company of Crows and Ravens
Our book today is a marvelous, boisterous volume titled "In the Company of Crows and Ravens," written by John Marzluff and copiously illustrated by Tony Angell.
This is a thoroughly wonderful work, sprightly and endlessly playful and inquisitive - much like its subjects, only minus the mischievous streak that all corvids display (the only way our authors could have duplicated this would have been to fill their index with page-references that go nowhere, title-headings that are totally evasive, etc. Corvids, in other words, love nothing so much as to mess with people - indeed, the absence of such features from this book is the strongest piece of evidence that it wasn't written by a raven).
This is natural history at its very best. Our authors give us the full range of their subjects' raucous life and times. We get history, folklore, and the very latest science pertaining to corvids, and we get it all in bouyant prose, accompanied by a delightful illustration on virtually every page.
We learn the huge and oddly uniform presence corvids occupy in all the many mythologies which feature them (basically, the role is always the same: the super-smart kid in the back of the class who's always talking, but only telling the truth about 45 percent of the time). We learn the various natural histories of the species throughout time. We learn the apparently endless anecdotal evidence that attests to the unique attributes of these birds.
We would be remiss if we didn't record our own favorite anecdote (not found in this book, alas):
A woman of our acquaintance once upon a time living in Saskatchewan, would routinely respond to her dog's porch-yelpings by putting out his twice-daily bowl of groud beef and various vegetable items. Often he wouldn't be right there on the porch when she laid the bowel down, but that was understandable - he could have wandered off, after all, distracted by something as canines will be. There came a time when the woman noticed that her dog was crying for his food-bowl more often than usual and getting thinner at the same time. After a considerable amount of puzzlement and then some clandestine surveillance, she learned the amazing truth: a raven, noticing that food could be gained from this house upon request, had learned how to make that request - by flawlessly imitating the poor dog's call. Every time the dog wandered away from the back porch, the raven would swoop down and call for takeout, hide while the bowl was being put out, and then chow down.
As David Quammen puts it in his wonderful essay "Has Success Spoiled the Crow?", this type of behavior is called cruising for a bruising. Corvids do it all the time.
This makes the reader naturally curious about how they do it - which means asking about their brains. Fortunately, Marzluff is right there with some fascinating information:
"Bird brains are not entirely like our brains. In all animals the forebrain is responsible for learning and memory. But in mammals like us, the enlarged parts of the forebrain are the hemispheres with the distinct convoluted surfaces known as the cerebrum. The frontal and temporal lobes of our cerebrums are the most important to memory, planning, problem solving, attention, and imitation. In smart birds like corvids and parrots, the inner portion of the forebrain, especially the nidopallium, is pronounced. The nidopallium is densely packed with nerve cells, making it an effecient storage, processing, and coordinating center. We know that the forebrain is important to learning and memory because it is largest in birds that excel in learning tests. Damage to it reduces a bird's learning ability. Another portion of the forebrain, known as the hippocampus, may be most important in spatial memory. In many corvids, chickadees, and tits (European chickadees) that cache seeds for future use, the hippocampus is huge. It may even expand during the autumn when caching is common and shrink during the spring when stored foods are used less."
Some of you will never have seen a raven, and even those of you who've seen crows probably haven't sat down and studied them. In either case, you can finally take heart: this splendid book is the next best thing.