BIAS IN THE DETERMINATION OF TEMPORAL ACTIVITY PATTERNS OF SYNTOPIC PEROMYSCUS IN THE SOUTHERN APPALACHIANS

We compared inferred activity patterns of two syntopic rodents, Peromy scus leucopus and P. maniculatus, in western North Carolina. Activity patterns were derived from capture-frequency data obtained from Sherma n Live-traps equipped with digital timers following different trapping protocols. We tested the hypothesis that no differences would be obse rved in frequency distribution of captures from trapping grids monitor ed only in the morning (control) compared with grids where captured an imals were released during the night and in the morning (treatment). D istributions of frequencies of captures on control and treatment grids were significantly different. On control grids, capture frequencies ( based on 3-h intervals) of both species were higher in the first 3 h a fter sunset and decreased thereafter throughout the night, but frequen cies of captures of both species were uniform throughout the night on treatment grids. photographic records from automated cameras suggested increasing levels of activity throughout the night. Activity patterns derived from camera data were different from those derived from the c ontrol and treatment grids. Inferences regarding activity patterns are sensitive to method and trapping-protocol bias.