Reproduction

Adult Male squirrels emerge from their hibernation in mid April. With the emergence of adult females a few weeks later, mating begins immediately (Elliott 1991). If females do not conceive then the mating process will continue up to another 5 weeks (Elliott 1991). For those females who are successful, gestation will last approximately 24 days (Murie et al 1980). During this time, the female will construct a natal den and increase her food intake to compensate for the pregnancy (Elliott 1991). Female Columbian ground squirrels have on average 3-5 offspring per litter (Murie et al, 1980).

After giving birth the mother will nurse her young for a month. During this month, the juvenile squirrels will develop their coats, and will become mobile (Elliott 1991). When finished nursing, the mother squirrel will leave the nest and plug the entrance to prevent predators from entering (McLean, 1978). Nursing ends when the juveniles emerge from their natal dens (Elliott 1991). From this point on, the juveniles are on their own when it comes to obtaining food, and a den. Juveniles on average will emerge in mid June.

Upon emerging as yearlings, male squirrels tend to disperse from their nests, while females will remain. This act of remaining at their birth site is known as philopatry. The male squirrels however will disperse from that territory, and will seek out a new place to live (Weddell 1989). Rather than colonizing an altogether new area, male squirrels will emigrate to a different territory. Here they will most likely live as a non-dominant male, unless the territory they have emigrated to lacks one for one reason or another (Manno, 2007).

This website was completed in partial fulfillment of the requirements for Biology 323, Animal Behavior, at Davidson College in the Spring Semester 2008.

Please send any comments, questions or suggestions regarding this website to Kevin Cook or Professor Verna Case.