Earth Almanac: November/December 2009

Canid Chameleon

As tundra slouches from the sun and the aurora borealis dances by day, the only canid to turn color with the seasons dons its luxuriant coat of white or, more frequently in the Aleutian and Pribilof Islands, light gray or steel blue. The diminutive Arctic fox, abiding above the Arctic Circle in North America, Eurasia, Iceland, and Greenland, can deal with temperatures as low as minus-58 degrees Fahrenheit. Small, rounded ears, fur that insulates better than any other in the mammal class, and thick hair covering the feet conserve body heat. The Arctic fox even carries its own blanket in the form of a bushy tail half the length of its body that it wraps around itself when at rest. Deep golden or orange-yellow irises protect the eyes from the fierce glare of the northern sun. Now Arctic foxes follow polar bears, gorging on their leftovers. At other times they feast on lemmings. Food is often cached, and in warmer months permafrost serves as a refrigerator. Eggshells found in the scat of Arctic foxes shortly before the arrival of nesting birds prove they cache eggs for nearly a year.

Upland Oysters

Throughout most of temperate North America and Eurasia, oysters are appearing in forested uplands. They are the fruits of ubiquitous fungi known as oyster mushrooms. After prolonged rain, look for the new, translucent caps stacked like oysters on the trunks of dead and dying hardwoods. Mature fruits, kidney- or fan-shaped, can reach diameters of 18 inches and, according to some estimates, produce 4 million spores per hour. Oyster mushrooms perform the vital forest function of breaking down lignin, thereby freeing nutrients for use by green plants. As oysters degrade the lignin, the wood softens, and insects move in. Then come the woodpeckers. Few mushrooms can rival oysters for flavor; smaller caps can be stir-fried, larger ones dipped in egg, rolled in breadcrumbs, and panfried. It’s hard to confuse oysters with dangerous fungi, and fungi that grow on trees are generally safer to eat than those that grow on the ground. Still, if you’re a novice, don’t pick any mushroom unless you’re in the company of an experienced collector.