Assessment of the Population Status of the Gray Bat (Myotis grisescens); Status Review, DoD Initiatives, and Results of a Multi-Agency Effort to Survey Wintering Populations at Major Hibernacula, 2005-2007

Abstract

Abstract : The gray bat (Myotis grisescens) is a federally listed endangered species known to occur on several U.S. Army installations in the eastern United States. Seven Army installations and one Air Force base have documented gray bat populations, and these facilities have undertaken programs to protect roosting and foraging sites important to the species. This report reviews the status of the gray bat throughout its range and assesses the population status of gray bats at major hibernacula in Arkansas, Missouri, Kentucky, and Tennessee. Survey records obtained from state agencies showed that in recent years gray bat populations have increased significantly in most primary summer and winter caves. In 2005 the Army cooperated with the U.S. Fish and Wildlife Service and other state and Federal agencies to undertake a range-wide survey of primary gray bat hibernacula. Hibernacula surveys were conducted from December 2005 - January 2007 in ii caves considered to be critical wintering sites. Results of the survey showed stable to increasing population levels across the species' range. Additionally, a Department of Defense Legacy project was implemented to support conservation efforts to assist with recovery of the gray bat. The project funded improvements and protection of several cave sites in Tennessee and Kentucky, hibernacula surveys of selected caves, and summer surveys of maternity caves in Tennessee. The Army Threatened and Endangered Species Research Program also provided support for these tasks. The current range-wide population of the gray bat is estimated at approximately 3.4 million bats.