Northwestern San Diego Pocket Mouse

(Chaetodipus fallax fallax)

This mecum-sized mouse occurs in the coastal and desert environments of southern California and northern Baja California. It has relatively small ears, with yellow to orange fur on its sides, a dark back, and a white underside. An excavator, it creates elaborate burrows, with separate chambers for sleeping and storing seeds. Grainivores, they can subsist on seeds alone.