http://ipm.ucanr.edu/PMG/PESTNOTES/pn7438.html
Primarily herbivorous, a ground squirrel’s diet changes with the season. After hibernation, they feed almost exclusively on green grasses and herbaceous plants. When plants begin to dry and produce seeds, ground squirrels switch their diets to seeds, grains, and nuts and will begin to store food. Ground squirrels will forage close to their burrows and their home range is typically within a 75-yard radius of their burrow.
For more information on Ground Squirrels, visit http://ipm.ucanr.edu/PMG/PESTNOTES/pn7438.html.