AN EXPERIMENTAL ANALYSIS OF ORIENTATION TO THE HOMESITE IN TWO RODENT SPECIES

Abstract

An experiment to determine the effects of celestial bodies and a view of the horizon on the ability of two rodents, Microtus californicns and Reithrodontomys megalotis, to orient toward the homesite was conducted in a grassland in central California. Mice were allowed to select an initial direction within a circle 11 ft in diameter on a plywood platform set up 425 or fewer feet from their home area, Under several sky conditions at night, or with a full view of the sun during the day, no evidence for orientation to the homesite was found. Individuals of R. megalotis with known homing success performed no better than did mice which failed to home. Orientation, if it occurred at all, did not occur in the first 10 minutes after release of the animals.