An Analysis of Migration as a Mortality Factor in the Gray Bat Based on Public Recoveries of Banded Bats

Abstract

Public band recoveries of Myotis grisescens over a 15 yr period are compared by month of recovery, age and sex. Peaks in recoveries coincide exactly with the major migrational movements in spring and autumn, and migration is considered to be a major source of stress leading to mortality. Juvenile mortality is significantly higher than that of adults and there is a slight but nonsignificant trend toward higher public recovery of males.