Homing and Orientation of Deermice

Abstract

A homing tendency was shown by deermice liberated at several points 200 to 1,600 yards from their place of capture. The proportion homing from 200 yards was 75%; from 1,600 yards three individuals (7.8%) returned. Some mice returned more than once and from release points that were located at two, three or four different directions from their home area. Juveniles homed less frequently than adults and subadults. Sex differences in homing success were not consistent, but suggest that males are more successful than females. The time intervals between release and recapture ranged from 8 hours to 25 days. Some individuals that were recovered two or more times after release at a single point returned faster after the second and subsequent releases, suggesting that return routes are imprinted during the first traverse of the route. Individuals liberated and recaptured in a circle of traps two times in succession also showed an ability to learn routes. Individuals released at the center of a circle of traps, and later recaptured at the circumference, showed no tendency to aggregate in the part of the circle that faced their home area. Failure to orient in new territory was also suggested by the record of three individuals that traveled many hundreds of yards to enter traps far distant from their initial capture sites. These results support the hypothesis that displaced deermice wander extensively, and at random, in relation to the “true” homeward course. Disruption of a pattern of attachment to the original home range and interactions with residents are two factors that might cause such wanderings.