Once again, the Cornell Website says it best:
The California Quail is a handsome, round soccer ball of a bird with a rich gray breast, intricately scaled underparts, and a curious, forward-drooping head plume. Its stiffly accented Chi-ca-go call is a common sound of the chaparral and other brushy areas of California and the Northwest. Often seen scratching at the ground in large groups or dashing forward on blurred legs, California Quail are common but unobtrusive. They flush to cover if scared, so approach them gently.
This family unit was seen on Lone Tree Rd in Hollister, CA.