The terrestrial mammal fauna of California includes about 160 species, with rodents making up more than half of this total. Roughly 30 mammal species are restricted to the desert regions of the state and thus are not considered part of the Mediterranean-climate region fauna. That leaves a total of about 130 terrestrial mammals native to the shrubland, grassland, woodland, and forest regions of California. These range from the mountain beaver, one of the most primitive living rodents, to the bighorn sheep, but also the striped skunk, mule deer, kangaroo rat, and more.
An additional five species have been extirpated from the state in historical times. These include the grizzly bear, wolf, bison, jaguar (only an occasional visitor in the past), and giant deer mouse. Turnover between habitats (beta diversity) accounts for most of the diversity of mammal faunas, with alpha and gamma diversity relatively low.
Counting resident, breeding, and migratory birds, about 350 total species can be found in California. Shore and marine birds make up 39 percent of this number. Passerines form the largest group of birds with 41 percent of the total. There are 21 species of hawks, vultures, and eagles, 13 species of owls, and 12 species of woodpeckers and flickers. Two bird species are endemic to California. These are the yellow-billed magpie and endangered California condor. In terms of passerine birds, the alpha diversity of bird species across landscape gradients peaks in closed woodland and forest habitats, while species turnover between habitats (beta diversity) is greatest in mid-elevation chaparral.
There are 54 species of amphibians and 69 species of reptiles within the political boundaries of California. The salamander fauna is especially notable with 36 species, 24 of which are endemic. The reptiles include two turtles and tortoises, 33 lizards, and 33 snake species. However, 38 reptile and amphibian species are found largely in the state’s desert habitats.
The native freshwater fish fauna of California includes 73 species of fish. Sacramento sucker, tule perch, sturgeon, and golden trout are among the state’s many bony fish. Anadromous species include steelhead trout and salmon,, whose numbers have declined precipitously due to dams and other water diversions.