Mating System

G. sabrinus on a “date,” courtesy of FlyingSquirrels.com and taken by Cy Hampson

Flying squirrels exhibit overlap promiscuity. One male mates with several females who live within his home range and mates tend to change by year, either because a new male takes over the home range or the females move to a new den. The male has no involvement in parental care, though the young are entirely altricial and the female will defend them fiercely.
G. sabrinus females come into estrus once per year, between March and May (Malamuth and Mulheisen, 1999). For G. volans, it is believed that females enter estrus twice per year and can birth two litters a year, once in the spring and again at the end of the summer (Stapp and Mautz, 1991).
Females are only reproductively receptive for one day. Presumably the male senses a chemical cue that the female is receptive and comes to mate with her. The female’s gestation period is on average 40 days, and the 1-6 young are born hairless, eyes shut, and must be nursed for the first 65 days (Fox and Mulheisen, 1999).

G. sabrinus, 7 hours old, courtesy of FlyingSquirrels.com, taken by Cy Hampson

In G. volans, young are entirely independent at 120 days and they are able to reproduce at 1 year (Fox and Mulheisen, 1999). G. sabrinus on the other hand is ready to leave the nest after 2 to 3 months and are reproductively mature the first summer after their birth (Malamuth and Mulheisen, 1999).

The patagium is visible from birth, as seen in this 12 day old G. sabrinus
Photo courtesy of FlyingSquirrels.com, taken by Cy Hampson

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.