Squirrels.

There are five kinds of tree squirrels in the park and one kind of small ground squirrel. The first category includes gray squirrels, red squirrels, two species of flying squirrels, and the fox squirrel, which is rare. The gray squirrels are found at low-to-mid elevations and are identical to those seen in many eastern cities.

Red squirrels are a northern species; here they live primarily at higher elevations. Because they chatter so insistently at intruders, they are called ''boomers.'" Flying squirrels are nocturnal, so they are rarely seen without special effort. The eastern chipmunk is a small ground squirrel. Unlike woodchucks, chipmunks take great care to conceal the locations of burrows and make a practice of storing food.