Rock squirrels are one of the largest members of the Sciuridae family, with adults measuring up to 21 inches (53 cm) in length. In front and on top, the squirrel's coat is a speckled grayish-brown; on the rear and bottom the gray becomes a more mottled brownish-black tone. They have a marked light-colored ring around their eyes, and pointed ears that project well above their heads. Rock squirrels have a long bushy tail with white edges. When alarmed, they whistle a short, sharp, oscillating call. The female rock squirrel has two litters a year, with three to nine young in each litter. The first litter is typically born between April and June, and the second is born between August and September.
Burrows and behaviors
Rock squirrels are able to dig burrows with their sharp claws and muscular legs. The burrows provide shelter, safety, living space and food storage. Burrow systems can be complex and lengthy as they are enlarged over a period of years. Entrances are usually hidden beneath rocks and can be larger than 3 inches in width. Rock squirrels in the northern reach of their habitat hibernate in their burrows during the colder months of the year. In southern areas, rock squirrels may not hibernate at all. They are active in the early morning and late afternoons when it is warm - when very hot, they may estivate. They are social, and live in colonies with several females and one dominant male that will fight other mature males to protect the group. There may be subordinate males at the outer boundaries of the group. (Desert USA)
The rock squirrel is predominantly a herbivore, eating mostly leaves, stems, and seeds. They also eat acorns, pine nuts, and fruits of native plants, including cacti. The rock squirrel forages for its food on a daily basis, both by climbing trees and bushes and searching for food on the ground. These foraging embarkments are generally short-lived, usually only lasting approximately 12 minutes at a time. Most foraging is done during the morning hours, to avoid the hotter parts of the day. Despite eating some of the food they find right away, rock squirrels usually bring a significant portion of the food they find back to a lookout point, where they can safely consume the rest of their meal. Occasionally, they may consume insects or the eggs of small nesting birds. The rock squirrel has also been known to eat their own kind, devouring the remains of squirrels that are already dead. The rock squirrel’s diet changes with the seasons, accustoming itself to what is available locally.
Rock squirrels create burrows for both shelter and safety. The burrows are large and complex, built with numerous entrances. They are also quick on their feet and great climbers. Rock squirrels also hibernate during the winter or estivate in the summer if temperatures are too high (March, 2). They can withstand long periods of time without water, some even up to 100 days (Oaks, 5).
- Linzey, A. V., Timm, R., Álvarez-Castañeda, S. T., Castro-Arellano, I. & Lacher, T. (2008). Spermophilus variegatus. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 8 January 2009.
- Helgen, Kristofer M.; Cole, F. Russel; Helgen, Lauren E.; and Wilson, Don E (2009). "Generic Revision in the Holarctic Ground Squirrel Genus Spermophilus". Journal of Mammalogy 90 (2): 270–305. doi:10.1644/07-MAMM-A-309.1. Archived from the original (PDF) on 22 October 2011.
"Rock Squirrel - Spermophilus Variegatus." Rock Squirrel. N.p., n.d. Web. 14 May 2015. “Rock Squirrel." S. N.p., n.d. Web. 14 May 2015. animals in the United States and Mexico June 26, 2015
Belding’s, California, and Rock Ground Squirrels by Rex E. Marsh Mamallian Species by Emily C. Oaks
- Data related to Otospermophilus variegatus at Wikispecies
- Media related to Otospermophilus variegatus at Wikimedia Commons
- Smithsonian rock squirrel article
- The American Society of Mammalogists species account
- Arizona-Sonora Desert Museum