Letters To The Editor

TO THE EDITOR

A Tiny, Brainy Bird

In "The Cost of a Brain" (12/99-1/00), Goran E. Nilsson discusses absolute and relative brain size and cites squirrel monkeys and some bats as having the most impressive brain-to-body-weight ratio (5 percent) of all mammals, including humans.

Birds also provide a useful perspective on brain size. The common raven,

which is the largest passerine (perching) bird and reputedly one of the most intelligent, has a brain volume of 17 cc. The golden-crowned kinglet, weighing in at about 5 grams, is probably the smallest passerine. The volume of its brain is only 0.34 cc (one-fiftieth that of the raven's). Relatively speaking, however, the golden-crowned kinglet's brain is huge: 6.8 percent (as compared with the raven's 1.3 percent) of body mass.

In general, the larger the brain, the more information-processing potential it has. But I speculate that being a passerine bird--perhaps like being a primate--requires a certain minimum amount of information-processing capacity, regardless of body size: hence the kinglet's relatively large brain.

Incidentally, just because a bird is large doesn't mean it has a big brain, even in absolute terms. A Rhode Island red has a pea-sized brain of only 3.1 cc (0.11 percent of body mass), even though it weighs twice as much as a raven.

Bernd Heinrich Burlington, Vermont

The Future of Vultures

I enjoyed "Cultureless Vultures," by Richard Milner (12/99-1/00). However, it is probably not possible for a species that learns, shares, and transmits information to be without culture. The condors will succeed to the extent their new culture allows. We'll just have to see what they teach their offspring.

While we can't have cultureless vultures, it is possible to have vultureless cultures. My thanks to those taking steps to prevent such an outcome.

Kent Hanson Everett, Washington

Pre-Adamite Pooh-Bah

As I read Stephen Jay Gould's "Pre-Adamite in a Nutshell" (11/99), I looked forward to what I thought would be his inevitable allusion to Gilbert and Sullivan's Mikado. I was disappointed to find that Gould had not somehow worked in the lines in which Pooh-Bah declares, "I am, in point of fact, a particularly haughty and exclusive person, of pre-Adamite ancestral descent. You will understand this when I tell you that I can trace my ancestry back to a protoplasmal primordial atomic globule."

Darel Roberts via e-mail

Duchamp's Deckchairs

Even after reading "Boats & Deckchairs," by Stephen Jay Gould and Rhonda Roland Shearer (12/99-1/00), I must admit that I would not have recognized the three objects in Marcel Duchamp's painting as rowboats if they hadn't been so labeled. And although I am usually good at seeing what is in an ambiguous image, try as I might, I couldn't see deckchairs in the picture from any perspective.

Do I lack the imagination to follow where Duchamp, Gould, and Shearer lead, or are Gould and Shearer defining "plausible" more broadly than I would?

Harold Bailey North Bend, Oregon

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