American Scientist

THE GRAIL BIRD: Hot on the Trail of the Ivory-Billed Woodpecker. Tim Gallagher. Houghton Mifflin, $25.

Anyone paying attention to the news recently has heard that the ivory-billed woodpecker, believed for more than half a century to be extinct, has been found living in the swamp forests of Arkansas. Although some ornithologists would like to see better evidence, many scientists have been convinced—primarily by sound recordings—that at least two of the birds remain. In The Grail Bird, author Tim Gallagher, who is the editor-in-chief of Cornell's Living Bird magazine, tells the story of how he tracked the giant woodpecker by following leads supplied by people who either had seen the bird in the 1930s and 1940s or claimed to have seen it more recently. One of these tips eventually led to a sighting during a canoe trip with a fellow "grail" seeker, Bobby Harrison (shown below decked out in camouflage with his camcorder), and the rest is now history.

Along the way, Gallagher weaves an engaging tale that is in part a detective story and in part a history of previous sightings. Readers will be infuriated by the greed and ignorance that eradicated the old-growth bottomland forests in which the woodpecker lived. And, given the widely publicized skepticism voiced during the summer of 2005, readers will not be surprised to learn that previous "rediscoverers" of the ivory-billed woodpecker were greeted with the kind of cynicism that's usually reserved for sightings of Bigfoot. Gallagher clearly "knows" what he saw—whatever the skeptics may think—but he also agrees that it is simply good science to acquire more evidence. To that end, the Cornell Laboratory of Ornithology and Arkansas Audubon Society are organizing another expedition to Arkansas this winter. They were looking for volunteers as this magazine went to press.—Michael Szpir

THE MATH INSTINCT: Why You're a Mathematical Genius (Along with Lobsters, Birds, Cats, and Dogs). Keith Devlin. Thunder's Mouth Press, $25.

Babies just a few days old have number sense. Psychologists have shown this by tracking the length of time infants stared at an image on a screen, finding that they could reliably tell the difference between one object and a collection of two objects, and between two objects and a collection of three objects. A dog trying to fetch at maximum speed a ball thrown over a lake diagonally to the water line seems able to figure out how far to run along the shore before plunging into the water, a problem that a human would need calculus to solve. So why is mathematics the bane of so many people?

In The Math Instinct, Keith Devlin tries to make the subject less intimidating by demonstrating that math is all around us. The book is chock full of animal examples, some of them just as surprising as a savvy ball-fetching dog.

Devlin seems uncertain what his readers will need to have explained. He reminds us that bats are mammals but doesn't define Ohm's Law. In the midst of eloquently explaining his area of expertise with infectious enthusiasm, he suddenly launches into a treatise on the relation between Fibonacci numbers and the golden ratio, one that is likely to make his target audience of math-phobes feel betrayed.

But Devlin does try to reassure readers by explaining that people faced with real-world calculations, such as price comparisons in a store, typically manage just fine, although they tend to use methods different from those they were taught in school. In the context of their daily lives, most people can solve the same problems that stump them on written tests. Devlin laments that in schools the abstract, representative number system, possibly humanity's greatest conceptual invention, is often transformed into a rote learning exercise, completely obscuring its majesty.

How can math be made more natural? Rather than memorizing universal rules, the ultimate trick, Devlin says, is to practice, because "familiarity breeds concreteness." It helps, he claims, to keep in mind what an incredible feat you are performing when you add 1/4 + 2/5.—Fenella Saunders

TIGER BONE AND RHINO HORN: The Destruction of Wildlife for Traditional Chinese Medicine. Richard Ellis. Island Press, $26.95.

On bear farms in China and Southeast Asia, workers insert catheters into the gall bladders of caged bears and, once or twice a day, "milk" the bears for their bile. Bear bile's purported curative properties make it a valuable commodity—every year about 7,000 kilograms of it are sold worldwide in various consumer products. Walk into a traditional Chinese medicine shop in a large North American city and you're likely to be able to buy pharmaceuticals containing bear bile, which is used to treat jaundice, hemorrhoids and a host of other ailments.

In Tiger Bone and Rhino Horn, prolific nature writer Richard Ellis assesses the threat posed to bears, tigers, rhinos and other animals by traditional Chinese medicine. He stresses the connection between conservation efforts and larger political and economic issues. For people living on just dollars a day, the chance to make hundreds or even thousands of dollars by killing a single animal is too good to pass up. There is some good news—the white rhino (above right) is a conservation success story. Ellis argues that whether the same will ever be said of other animals coveted for their alleged healing properties depends primarily on the choices made by the world's dominant species.—Amos Esty