The California ground squirrel (Otospermophilus beecheyi) is native to the United States from western Washington to Baja California.
Ground squirrels are mottled grey and light brown with the shoulders and neck a lighter grey. The tail is furry but not as fluffy as a tree squirrel. Adults are about 12 inches long and stocky.
California ground squirrels dig their own burrows and spend most of their life no more than 80 feet from the burrow entrance. Some burrow systems are communal with many individuals using the same space. Ground squirrels are omnivorous and feed on seeds, nuts, fruit and large insects.
Ground squirrels have one litter per year with 5 to 11 pups per litter. Young squirrels are able to reproduce when one year old and can live 6 years in the wild. Their main predator is the rattlesnake, and some populations of ground squirrels are resistant to rattlesnake venom.
Ground squirrels are considered a major pest as their burrows undermine structural foundations and trees – causing them to fall. They gnaw on ornamental plants and trees causing substantial damage to gardens and parks. Their burrow openings can also create pits that result in leg injuries for stock animals and horses.
Ground squirrels carry a lot of fleas. There may be up to 25 fleas on each squirrel, and a large colony can house thousands of fleas in one burrow system. Ground squirrels are susceptible to diseases like plague and tularemia, and entire colonies may be wiped out by these diseases. Once a burrow system has been vacated, it may be recolonized by other animals such as Norway rats, or if the burrow is distant from humans, burrowing owls.
Find out more information about ground squirrels and how to manage them from UC IPM
Find out more information about distinguishing squirrel species from University of California
Page last reviewed: August 24, 2021