Apparently, litte data is available for the current status of this bat species. Bat Conservation International lists Eumops perotis on its Threatened and Endangered Bats List due to the the fact that it uses only select drinking sites and is severely limited by the availability of drinking water. Because its wing structure is adapted for fast and straight-line flight, it is unable to drink from water sources less than 30 m long. As a consequence, western mastiff bats are no longer found in many previously occupied areas and populations may be in decline (Acker, 2001).
Temperate North American bats are now threatened by a fungal disease called “white-nose syndrome.” This disease has devastated eastern North American bat populations at hibernation sites since 2007. The fungus, Geomyces destructans, grows best in cold, humid conditions that are typical of many bat hibernacula. The fungus grows on, and in some cases invades, the bodies of hibernating bats and seems to result in disturbance from hibernation, causing a debilitating loss of important metabolic resources and mass deaths. Mortality rates at some hibernation sites have been as high as 90%. While there are currently no reports of Eumops perotis mortalities as a result of white-nose syndrome, the disease continues to expand its range in North America.
US Migratory Bird Act: no special status
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
- Cryan, P. 2010. "White-nose syndrome threatens the survival of hibernating bats in North America" (On-line). U.S. Geological Survey, Fort Collins Science Center. Accessed September 16, 2010 at http://www.fort.usgs.gov/WNS/.
- National Park Service, Wildlife Health Center, 2010. "White-nose syndrome" (On-line). National Park Service, Wildlife Health. Accessed September 16, 2010 at http://www.nature.nps.gov/biology/wildlifehealth/White_Nose_Syndrome.cfm.