One subspecies of the White-eared Pocket Mouse may be extinct, and the other is extremely rare, consisting of isolated, relict populations near the western Mojave Desert in California. White-eared Pocket Mice are nocturnal and probably closely resemble Great Basin Pocket Mice in their habits. Learn more about the Perognathus alticola, more commonly known as a White-eared Pocket Mouse, in this easy-to-read species overview by the Smithsonian's National Museum of Natural History.