Social Spacing

North American flying squirrels are not territorial. Both males and females use home ranges based on the availability of food and dens. A home range generally includes several different kinds of nests, most of which are already abandoned cavity nests. Most common types of nests are:

Refugia nests – used for diurnal nesting and resting during night outings
Natal nests – used for rearing of offspring
Aggregate nests – during the winter months, many flying squirrels will share one nest together to conserve heat (Patterson, 2008); up to 50 individuals have been observed sharing one nest, including males, females, and juveniles (Layne, 1994)

Communal Nesting, Photo courtesy of FlyingSquirrels.com, taken by Cy Hampson

It has also been found that temperature does not have a strong effect on the presence of communal or aggregate nesting; southern flying squirrels in Florida are observed in aggregation just as much or more than the same species farther north (Layne, 1994).

Home Ranges

Home range size differs considerably among males and females. The male range is approximately twice as large as the females, with average range sizes 7.8 ha and 3.8 ha, (approximately 19.3 and 9.4 acres) respectively (Stone, Heidt, Caster, and Kennedy, 1997). Home range size depends largely on the availability of food and nesting cavities and is highly variable for both males and females. Females will aggressively defend their home range, and specifically their natal nest, during early offspring development (Dolan and Carter, 1977).
Within their home range, flying squirrels live primarily within cavity nests. In 1981, Maser et. al. showed that there is distinct segregation of the sexes within the nests, with adult males tending to use nest boxes while adult females and juveniles tended to use the preferred cavity nests (Maser, Anderson, and Bull, 1981). During the winter months, G. volans can sometimes enter a state of torpor within its nest, dropping its body temperature to as little as 22°F and taking up to 40 minutes to reawaken. It only does this in times of food scarcity or extreme cold, and this behavior has not been observed in G. sabrinus (Whitaker, 1996).
In the few areas that the habitats of G. volans and G. sabrinus overlap, namely the Appalachian Mountains and the Great Lakes area, the two species can live in close proximity with little interaction. The will choose to make their nests in different types of trees (hardwoods for G. volans and conifers for G. sabrinus) and food is usually plentiful for both. If, however, two individuals do come into conflict over a nest site, the smaller, more aggressive southern species generally wins out (Whitaker, 1996).
In an extensive study on the areas of overlap of the two species, Weigl found that there is little competition between the two due to climate. G. volans is more adapted to warmer climates, and in the winter must reside in cavity nests, often in aggregates, eating nuts to maintain a high enough energy level. G. sabrinus on the other hand is well suited to the colder climate and can use leaf nests outside. Thus there is little reason for the two species to compete, and they have even been found sharing nests (Weigl, 1978).

G. sabrinus using a cavity nest, courtesy of FlyingSquirrels.com

Dominance

There is little evidence of whether flying squirrels have a dominance hierarchy. Whitaker (1996) does say that when mating, females prefer dominant males. As this is the only report of such a hierarchy, more research and observation is needed to confirm or refute the presence of dominance among North American flying squirrels. However, based onthe type and size of their home ranges it is likely that there is a dominant male who “owns” a home range with several female territories, and that this male will be mated with preferentially by the females within his home range.

This website was completed by Kara Earle in partial fulfillment of the requirements for an undergraduate course -- Biology 323: Animal Behavior -- at Davidson College in the Spring Semester 2008.