Friday, Feb. 1, 2002
* Japanese name: Nihon risu
* Scientific name: Sciurus lis
* Description: The Japanese squirrel is an arboreal species, which means it lives in trees. It has a long, bushy tail, large tufted ears and sharp claws. Its fur changes color according to the season. In summer, the fur is red-orange. In winter, because these squirrels do not hibernate, the fur becomes camouflaged, turning gray or light-brown and white under the chin and on the belly. Body length is 18-22 cm.
* Where to find them: Quiet woodlands, from Honshu to Kyushu, and nowhere else -- the species is only found in Japan. This squirrel is most active in the early morning, and during the day they often take a quick nap in a tree. They build several ball-shaped nests in trees and switch between them. One reason for moving house might be to avoid parasites like fleas and ticks that build up in their bedding material. They have three to six offspring.
* Food: Nuts, seeds and young leaves. Squirrels' incisors (cutting teeth) continually grow to compensate for the wear that comes from their herbivorous diet.
* Special features: Japanese squirrels are well-adapted to life in trees. When they leap between trees, they use their tail to steer, and when they land, the tail slows them down, like a parachute. At rest the tail lays along the squirrel's back. They can rotate their hind feet 180 degrees to help them climb down trees. Many biologists studying cognition (memory and spatial perception) are interested in squirrels because of their food-hoarding behavior. Squirrels have to prepare for the annual winter food shortage, so they store nuts and seeds in caches to retrieve later. However, the forest undergoes changes as winter comes on, and the hungry squirrel must be able to remember the location of its hidden food. Some food caches are never found -- an important factor aiding the dispersal of seeds. Other caches are found -- but by a different squirrel. Squirrels have no qualms about stealing the food of others.