Richardson's Ground Squirrel

activity

Activity patterns. Richardson’s Ground Squirrel is diurnal and hibernates in burrows for c. 6 - 8 months. Emergence begins in March or April, with adult males appearing first and adult females emerging about c. 2 - 3 weeks later. Adult males hibernate in June, followed by adult females soon after, but juvenile females only hibernate in August and juvenile males remain active and reach adult size as late as October.

Sciuridae

biology_ecology

Movements, Home range and Social organization. Males disperse from their natal area during their first year oflife, although females remain in or near the natal area. Related females are amicable within the kin cluster, but aggressive to unrelated individuals, chasing them away. Burrows consist of extensive networks of passages and entrances, with multiple chambers that extend to a depth of 1 m. Individuals hibernate alone, but often share the burrow system with other individuals. Males store seeds within the nest chamber to consume in preparation for next spring’s mating season. Rigors of mating season result in male life spans that rarely exceed two years, whereas females live up to six years. Alarm calls of Richardson’s Ground Squirrel are a long shrill burst that elicits vigilance for terrestrial predators and a short “ chirp ” that causes surrounding individuals to escape to cover in response to aerial predators. Number of callers in a population indicates severity of the potential threat, and location and order ofcalls indicate direction of avian predators.

Sciuridae

breeding

Breeding. Mating occurs 3 - 5 days after emergence of females, and male-male competition is intense during the two or three weeks of breeding season. Many males die due to injuries and loss offat reserves. Females mate with several males, and a copulatory plug forms after each mating. After a gestation of ¢. 22 - 23 days, a litter of 3 - 11 young, with an average weight of 6 - 8 g (4: 4 - 9 - 6 g, n = 147) each, is born within a grass-lined nest chamber in burrow. Young emerge from natal burrow at c ¢. 28 - 30 days old, are weaned 1 - 2 weeks later, and are sexually mature at one year. Females produce only onelitter a year.

Sciuridae

conservation

Status and Conservation. Classified as Least Concern on The IUCN Red List. Current population trend is stable and there are no major threats to Richardson’s Ground Squirrel. Because it consumes cereal grains, it is considered a pest and is poisoned in some agricultural areas. There are several protected areas within the distribution of Richardson’s Ground Squirrel.

Sciuridae