Their aerial abilities are made possible by a loose fold of skin, called the patagium, that spans from wrists to ankles. When a flying squirrel leaps from a tree, it extends its arms and legs outward, stretching the patagium to act like a parachute or glider wing. In flight, the animal is able to steer adeptly right or left to avoid obstacles. Before touchdown, usually on a tree trunk, the animal lifts its tail and veers sharply upward to bring its feet into landing position. Though flying squirrels spend much time in trees, they descend frequently to the ground in search of food.
Truffles are underground fungi that bear the spores of so-called ectomycorrhizal fungi.
Such fungi live in symbiosis with trees. The fungi form a coating on roots and probe the soil to help the trees take up nutrients and water. In return, the fungi receive sugars produced by the trees through photosynthesis. Ectomycorrhizal fungi can be extraordinarily abundant in healthy forests, creating vast networks of fungal threads through the soil. During spring and fall, says Dan Luoma, an assistant professor of forest science at Oregon State University, a typical acre of Pacific Northwest woodlands may harbor anywhere from two to eight pounds of truffles.