A Study of Homing of Meadow Mice

In an investigation of the means by which meadow mice find their way home, more than 700 mice were displaced. The percentage of mice homing decreased with increasing displacement distance, but the average time of homing from all distances was similar. Mice released a second time in the same location returned in high proportions independ- ent of displacement distance indicating that mortality was a minor factor in preventing homing. These mice did not substantially improve their speed of homing, suggesting that homing had been as direct after the first displacement as after the second. Mice released at long distances in apparently unfamiliar terrain seemed to make little effort to search for home and remained to be captured repeatedly near the release point. At such distances the pattern of dispersal shown by captures near the re- lease point indicated no orientation toward the homeward direction. Mice retained through the summer in two-acre enclosures demonstrated less homing ability than mice from neighboring populations allowed free- dom to wander. These various results are interpreted to support the hypothesis that homing is accomplished through prior knowledge of the terrain and to a minor extent through random wandering.