Managers are increasingly faced with having to translocate a species, without a full understanding of its natural history. One such species is the San Joaquin antelope squirrel, a California-threatened species endemic to the San Joaquin Desert. In particular, little is known about the species diet preference, which could improve translocation outcomes by targeting areas with highly preferred food species. It is also unclear how plastic the species’ diet preferences are – in other words, how well individuals would cope with novel food items. We performed cafeteria trials in two pastures of the Carrizo Plain National Monument to assess overall preferences, differences in native and exotic species, and response to novel food sources. We found that grasshoppers and the green vegetation from shrubs (genus Atriplex and Ephedra) were the most preferred food items, but shrub preference declined over the course of the trials.