| The Spiny Pocket Mouse is somewhat shaggy. Its spines, which are mostly on the rump, are not nearly as stiff as porcupine quills. Like quills, they are modified hairs. This Pocket Mouse occurs throughout most of Baja California, Mexico, and on some of the islands off the coast. In the United States, it occurs only in extreme southeastern and south-central California west of the Colorado River. The Rock Pocket Mouse lives east of the river in identical habitat. Because these animals choose places of little agricultural value, their habitats are probably safe from development and their futures as species secure.
Merriam, C.H., 1889. Preliminary revision of the North American pocket mice (genera Perognathus et Cricetodipus auct.) with descriptions of new species and subspecies and a key to the known forms, p. 21. North American Fauna, 1:1-36.
Mammal Species of the World
Mammalian Species, American Society of Mammalogists' species account
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