Use of woody ground litter as a substrate for travel by the white-footed mouse, Peromycus leucopus

Use of woody ground litter by white-footed mice (Peromyscus leucopus) as a substrate for travel was studied in a middle-aged, deciduous forest in southcentral Pennsylvania using a fluorescent pigment tracking technique. Mark-recapture data on 45 P. leucopus and mapped trails of 17 individuals were obtained from April through December 1986. Following collection of data on the movements and habitat utilization of white-footed mice in an unmanipulated system, selected quadrats within the study site were cleared of all woody ground litter greater than 10 mm in diameter to assess the importance of such litter on habitat utilization and movements by P. leucopus. There was a significant decrease in the number of captures of white-footed mice on cleared plots between the pre- and post-litter removal phases of the study. Although woody ground litter comprised only an estimated 8.2% of the ground cover on the study site, approximately half the total distance travelled by P. leucopus was on woody ground litter. The use of woody ground cover for travel by P. leucopus may represent a trade-off between the risks of predation from rattlesnakes (Crotalus horridus) that use ground litter as ambush sites and nocturnal raptors that are more common and employ auditory cues to locate prey.