Range and Habitat
California ground squirrel and Belding's ground squirrel both cause damage in California. Management strategies differ between the two, so it is important to correctly identify the squirrel that is causing damage on your property. The common name "California ground squirrel" includes both Otospermophilus beecheyi and O. douglasii, but management for these two species does not differ.
California Ground Squirrel
The California ground squirrel is found throughout most of California and extends south into the northwestern part of the Baja peninsula. It is also found in western Nevada and can be found north of the Columbia River in south central Washington and throughout western Oregon.
The California ground squirrel inhabits natural rangeland, agricultural field edges and fence lines, pastures, grain fields, orchard crops, slopes with scattered trees, rocky ridges, roadsides, open grassy areas, and coastal areas. It does not prefer thick chaparral or dense woods. Although California ground squirrel populations generally thrive where the winters are mild, there are known populations in the central Sierra Nevada Mountains at altitudes of over 7,000 feet.
Belding's Ground Squirrel
Belding’s ground squirrel occupies the northeastern part of California. It can also be found in eastern Oregon, southwestern Idaho, and the north-central portion of Nevada. In Oregon and northeastern California, Belding’s ground squirrels are the most numerous and damaging ground squirrels affecting agriculture. Unlike the California ground squirrel, it inhabits the interior of agricultural fields, making it far more damaging.
Belding’s ground squirrels live in natural meadows and grasslands as well as agricultural fields. They cause considerable damage in alfalfa, irrigated pastures, and the margins of grain fields. At higher elevations, they may occupy meadows in forested areas. However, they generally avoid forests or dense brushlands.