WINTER WORLD

An array of ways to beat the cold when central heating isn’t an option, from National Book Award nominee Heinrich (Racing the Antelope, 2001, etc.).

The cleverness of evolutionary design is everywhere on display in this look at how animals cope with winter. Like the good teacher he must be at the University of Vermont, Heinrich takes pains to be clear, laying a groundwork of information for what follows. He starts at the molecular level, explaining the properties of water and the difference between heat and temperature, then providing an outline of various life-maintenance techniques used by creatures from insects to bears—methods that include aestivation and brumation, freezing point depression, antifreeze, ice-nucleation sites, thermal hyteresis, and supercooling, all allowing these organisms to survive the “regularly occurring famine” that winter brings on its heels. Heinrich’s description of snow’s thermal qualities makes it understandable that a broad range of animals use it for insulation, but what he clearly delights in are the startling discoveries resulting from fieldwork undertaken by both himself and others. We learn about the differing bill morphologies of birds, about the spring peepers and chorus frogs that freeze solid after suffusing their cells with glucose, the arctic ground squirrels that heat up from their torpor to get a little REM sleep, and the chronobiology of flying squirrels as they set their internal clocks without external cues. There’s the role of camouflage, as in the weasel turning white, and the unique architecture of birds’ nests (“the more different or exotic the nest appearances there are for different species, the less any one would stand out to predators”), not to mention the many insects, whose “success is derived from exploiting individual specificity.” Heinrich relates each creature’s method as a story, slowly revealing its canny, outrageous, or dumbfounding aspects—letting the reader sit back and marvel.

The stories are plain engrossing—in their elucidation, their breadth of examples, and their barely contained sense of awe and admiration. (Drawings throughout)