Winter is a great time to do one of my favorite things, squirrel watching. Bernheim Forest is home to three species of tree squirrels.
Everyone knows the bird feed stealing gray squirrel, Scirurus carolinensis. It is seen in many city parks and suburbs, but it can also be found in the mature woods found here at Bernheim. The other two species of squirrels are less known by people, and are fox squirrel (Scirurus niger) and southern flying squirrel (Glaucomys volans). Fox squirrels are the largest tree squirrels native to North America, and are found in more open wooded areas. They can also be found in shrubby hedgerows near prairies. The fox squirrels are found in more open forests with an open understory, while gray squirrels prefer more closed understory. The easiest way to distinguish the fox squirrel from the gray squirrel is that they are larger and usually have a tan underside.
The third and rarely seen tree squirrel species, the southern flying squirrel, is more nocturnal than the other two species of tree squirrel, which means they are active at night. They are easily distinguished from the other species by the flying membrane, or the flap of loose skin that extends from the wrist to the ankle. Southern flying squirrels don’t fly; instead this loose skin allows them to glide from tree to tree. They can glide great distances, and from a height of 20 meters they can glide 60 meters avoiding obstacles such as trees.