TEMPORAL ACTIVITY OF SYNTOPIC PEROMYSCUS IN THE CENTRAL APPALACHIANS

Partitioning of time may allow coexistence of syntopic species that occupy similar ecological niches. Circadian activities, expressed as hours after sunset, were described and potential for temporal segregation examined for Peromyscus leucopus noveboracensis and Peromyscus maniculatus nubiterrae at low densities in a deciduous forest of western Maryland. Sherman live-traps equipped with digital timers recorded capture time of individuals of these two species from spring 1988 through winter 1989. Nocturnal activity of P. leucopus was unimodal, whereas activity of P. maniculatus was variable. Onset of nocturnal activity for both species was closely tied to sunset across seasons. A significant difference (P < 0.05) was observed between activity patterns of these species in spring, when a greater proportion of captures of P. maniculatus than that of P. leucopus occurred in the early morning hours. This temporal segregation during the breeding season may result in fewer interspecific encounters at a time when energy must be conserved for reproduction.