A major food source for flying squirrels is mushroom fungi, or truffles of various species. They also eat lichens, mushrooms, all mast-crop nuts, tree sap, insects, carrion, bird eggs and nestlings, buds and flowers. The squirrels are able to locate truffles by olfaction (or smell), though they also seem to use cues such as the presence of coarse woody debris, indicating a decaying log and spatial memory of locations where truffles were found in the past. The northern flying squirrel is also known to cache food (hoard or hide food from other animals) when food supplies are lower. These caches can be found in tree cavities and as in the squirrels’ nest. Lichens and seeds are commonly stored by these creatures.
Nests made by Northern Flying Squirrels:
The nests of Northern Flying Squirrels are typically found in holes of trees. These creatures prefer a large-diameter trunk and dead trees and will also build outside leaf nests called dreys. They sometimes use cavities created by woodpeckers. Suitable nest sites tend to be more abundant in old-growth forests, leading to an increased population is such areas. However, harvested forests can be managed in such ways that are likely to increase squirrel numbers as well. Except when rearing young, the squirrels will shift from nest to nest frequently and often share nests. In one nest, over 50 individual squirrels can be found cohabiting, although more commonly nests contain 2-5 individual squirrels. The sharing of nests by flying squirrels is important in maintaining body temperature in the winter as flying squirrels do not hibernate and are active year-round.