| Columbian Ground Squirrels live in large colonies, and both males and females are territorial. Males defend a small core area within their home range, trying to keep other males from access to females. Females defend areas where their nest burrows are located. Individuals chase each other, fight, and mark their territories with scent glands located at the edge of the mouth, side of the head, and back. Columbian Ground Squirrels are active for about 90-100 days per year, and they do not awaken to eat stored food during their long hibernation, so weight gain during the active period is crucial to survival. Males emerge first from hibernation, before green vegetation is readily available, and must rely on modest stores of food from the previous year. Females emerge later, mate, and after about a month, have a litter of 3-5 pink and hairless young. Males generally begin mating at three years of age, and females at two.
Ord, G., 1815. "North American Zoology" in A new geographical, historical, and commercial grammar, (W. Guthrie, ed.), 2nd ed., Lippincott, Philadelphia, p. 303.
Mammal Species of the World
Mammalian Species, American Society of Mammalogists' species account
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