Townsend’s Ground Squirrel, Urocitellus townsendii
The Townsend’s ground squirrel, or Urocitellus townsendii, can be found in many areas of the United States. The range of this squirrel includes south-central Washington, western Utah, east Oregon, southern Idaho, and most of Nevada. They can also be found in the eastern extremities of California. There are seven subspecies of this type of squirrel including Merriam’s ground squirrel and Piute ground squirrel.
Townsend’s ground squirrels prefer to live in arid environments, most often near water sources like irrigated fields or desert springs. They will also choose habitats in old fields, ridge tops, and hillsides. The squirrels will burrow into well-drained, deep soil to make their homes. These burrows are frequently grouped together, and are not only used for shelter, but also for food storage and protection from predators. Although most Townsend’s ground squirrels live in colonies, some prefer to live alone. Each burrow will house only one squirrel, unless a mother has pups.
The dormancy period, or aestivation http://en.wikipedia.org/wiki/Estivation , of the Townsend’s ground squirrel depends on the conditions of its environment occurring during the hotter months of the year. They can remain dormant for seven and half to nine months, entering anywhere from late spring to early summer. If there is not much to forage from, they will estivate for a longer period.
The female Townsend’s ground squirrel breeds in the first year of its life, as well as most males. Some males, however, will not breed until their second year. In most cases, breeding occurs after hibernation, between late January and early February. Piute ground squirrels, on the other hand, breed later from mid-February to early March. These squirrels will produce one litter a year, and can have anywhere from six to ten hairless pups, who are born with their eyes closed. Their eyes will open between nineteen and twenty-two days of age, and they are weaned shortly after.
The main diet of the Townsend’s ground squirrel is green vegetation, although insects and seeds will also be consumed. They will eat green grasses until just before the aestivation period, when seeds become a primary source of nutrition. They will also consume large amounts of a shrub called winterfat, if available, and may eat less of other types of shrubs.
The conservation status of the Townsend’s ground squirrel is vulnerable. They are the major source of food for ferruginous hawks in the Great Basin and Columbia Plateau areas, as well as prairie falcons. Other predators that this squirrel serves an important role for are gopher snakes, badgers, coyotes, and common crows.
Image Caption: Townsend’s ground squirrel. Credit: BLM/Wikipedia