Seasonal Activity Patterns of Rodents in a Sagebrush Community

Twelve species of nocturnal rodents were studied on a 2.7-hectare plot of sagebrush desert in west-central Nevada. Six species, Dipodomys merriami, D. ordii, D. panamintinus, D. microps, Onychomys torridus, and Peromyscus maniculatus, were active throughout the year. Four species, Perognathus longimembris, P. formosus, Microdipodops megacephalus, and Reithrodontomys megalotis, hibernated and were active only in spring, summer, and autumn. Onychomys leucogaster and Neotoma lepida were trapped intermittently throughout the year but were not permanent residents of the area. Differences in time of daily activity were found between potential competitors demonstrating a degree of temporal isolation. Time after sunset and amount of moonlight were the two most important factors correlated to rodent activity. Ambient temperature, wind, cloud cover, precipitation, and water vapor pressure had little effect on activity except when extreme conditions prevailed. (auth)