27 species of mammals have been recorded from the James Reserve.  They range from the conspicuous western gray and California ground squirrels, to the secretive and rarely seen mountain lion.  Some are subterranean such as the broad-footed mole and the valley pocket gopher and only their excavations provide evidence that they are here.  Some such as the 8 species of mice, rats and voles are nocturnal, providing food for owls and other night roaming mammals such as coyotes, foxes, and bobcats. All in all, a small but rich assemblage of this group can be found at the James.