The red squirrel is alert, raucous and energetic. About half the size of the gray, the red measures about a foot from nose to tail tip and weighs about 5½ ounces. In summer its fur is a rich, rusty brown, turning grayer in winter, when this squirrel also develops prominent ear tufts. The undersides are off-white.
The red squirrel is sometimes called a chickaree or a pine squirrel, reflecting its preference for nesting in conifers. Behavior, feeding habits and denning practices are generally similar to those of gray and fox squirrels, although reds sometimes nest in holes at the base of trees. They enjoy eating the immature, green cones of white pine. Unlike fox and gray squirrels, reds do not bury nuts singly, preferring a large cache often in a hollow log for storing food.
The breeding season for red squirrels begins in late winter, with 3 to 6 young born in April, May or June after a 40-day gestation period. Reds have strong territorial instincts, often defending food sources and den trees against intrusion, and will even aggressively drive off trespassing grays.