TEMPORAL NICHE SEPARATION OF DESERT COTTONTAILS (SYLVILAGUS AUDUBONII) AND BLACK-TAILED JACKRABBITS (LEPUS CALIFORNICUS) IN THE CHIHUAHUAN DESERT

Abstract

Desert cottontails (Sylvilagus audubonii) and black-tailed jackrabbits (Lepus californicus) occur in sympatry throughout the southwestern United States and northern Mexico, including in the Chihuahuan Desert. Their ecological niches are similar but separated by variations of diet and microhabitat. To determine if niche separation may be supplemented by differing times of foraging activity, I first tested various lures and baits and determined the optimal attractant for camera stations to be alfalfa hay and apple juice. I then observed desert cottontail and black-tailed jackrabbit activity at baited and control camera stations. Peak seasonal foraging activity occurred in winter for desert cottontails and in spring for black-tailed jackrabbits. Early morning activity peaked in black-tailed jackrabbits 1 h later than in desert cottontails, but otherwise general diel activity levels were similar between the two species. However, times of peak feeding, as determined by comparisons of baited and control stations, were clearly separated. Thus, niche separation between desert cottontails and black-tailed jackrabbits in the Chihuahuan Desert may be increased by differing time distributions of foraging activity.