Bailey’s pocket mouse is a large-bodied pocket mouse of the Sonoran Desert, and one of the few rodents anywhere able to live on jojoba seeds that poison most other animals. Open occurrence databases hold 4,289 Arizona records for it, nearly all from survey trapping and specimens, since the species is nocturnal and seldom photographed.
A desert seed specialist
This is a mouse of the warm Sonoran lowlands and their rocky upland fringes, densest in the desert around Tucson and thinning north toward Phoenix. The records bear that out, with Pima and Pinal counties holding the great majority. It forages at night for seeds, packing them into fur-lined external cheek pouches to carry back to a burrow, and it is best known for a rare digestive trick: it can detoxify and eat the waxy seeds of jojoba, a resource closed to nearly every competitor.
After dark and underground
Bailey’s pocket mouse is active through the year rather than tied to one season, but everything it does happens after dark and much of it below ground. By day it stays sealed in a burrow against the desert heat, which is why the photographic record is so sparse next to the trapping record. A daytime search turns up only the burrow entrances and the faint trails between shrubs, not the animal itself.
Common questions
Where is it most often recorded in Arizona? The Sonoran Desert of the south-central and southeastern basins, especially in and around Pima County near Tucson.
What does it eat? Mostly seeds, including the jojoba seeds that are toxic to other rodents, gathered and carried in its cheek pouches.
Full species profile
