Great Basin Naturalist Memoirs


Activity patterns of desert heteromyids are characteristic of many nocturnal rodents, with a peak of activity near dusk and a second prior to dawn. Seasonal activity varies with environmental conditions, going from activity throughout the winter in larger species to extended periods of torpor by smaller pocket mice. The rodents forage primarily for seeds, with pocket mice tending to feed under shrubs and on relatively low-density seed patches and kangaroo rats frequently foraging in the open for relatively high-density seed patches. The animals are usually solitary, with aggression exhibited between and within species. Burrow construction can be simple to extensive. Communication occurs visually, with odor (especially at sand bathing sites), and with sound (drumming). Reproductive behaviors are characterized by brief courtships and copulation. Subsequent maternal behavior includes nursing, grooming, and other forms of general maintenance. Individuals spend considerable time autogrooming, presumably to enhance temperature regulation and reduce parasite attack. Although many of the behavioral patterns seen in heteromyids are similar to other rodents, locomotory and auditory specializations appear to yield behaviors characteristic of the group of rodents.