Midwest Region Endangered Species Conserving the nature of America

Endangered Species Program


The mission of the U.S. Fish and Wildlife Service's Endangered Species program is conserving and restoring threatened and endangered species and their ecosystems.




U.S. Fish and Wildlife

Service in the Midwest


The Midwest Region includes Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, Ohio and Wisconsin. Find a location near you.


The Midwest Region includes Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, Ohio and Wisconsin.
Find a location near you »

Gray Bat (Myotis grisescens)

Fact Sheet

PDF version


Gray Bat

Photo by Adam Mann

The gray bat is an endangered species. Endangered Species are animals and plants that are in danger of becoming extinct. Threatened species are animals and plants that are likely to become endangered in the foreseeable future. Identifying, protecting, and restoring, endangered and threatened species is the primary objective of the U.S. Fish and Wildlife Service's endangered species program.


What is the Gray Bat?


Gray bats are distinguished from other bats by the unicolored fur on their back. In addition, following their molt in July or August, gray bats have dark gray fur which often bleaches to a chestnut brown or russet. They weigh 7-16 grams. The bat's wing membrane connects to its ankle instead of at the toe, where it is connected in other species of Myotis.



With rare exceptions, gray bats live in caves year-round. During the winter gray bats hibernate in deep, vertical caves. In the summer, they roost in caves which are scattered along rivers. These caves are in limestone karst areas of the southeastern United States. They do not use houses or barns.



Females give birth to a single young in late May or early June.


Feeding Habitats

The bats eat a variety of flying aquatic and terrestrial insects present along rivers or lakes.



The gray bat occupies a limited geographic range in limestone karst areas of the southeastern United States. They are mainly found in Alabama, northern Arkansas, Kentucky, Missouri, and Tennessee. A few can be found in northwestern Florida, western Georgia, southeastern Kansas, southern Indiana, southern and southwestern Illinois, northeastern Oklahoma, northeastern Mississippi, western Virginia, and possibly western North Carolina.


Why Is the Gray Bat Endangered?

Human Disturbance

Gray bats are endangered largely because of their habit of living in very large numbers in only a few caves. As a result, they are extremely vulnerable to disturbance. Arousing bats while they are hibernating can cause them to use up a lot of energy, which lowers their energy reserves. If a bat runs out of reserves, it may leave the cave too soon and die. In June and July, when flightless young are present, human disturbance can lead to mortality as frightened females drop their young in the panic to flee from the intruder.


Habitat Loss or Degradation

Many important caves were flooded and submerged by reservoirs. Other caves are in danger of natural flooding. Even if the bats escape the flood, they have difficulty finding a new cave that is suitable.


Cave Commercialization and Improper Gating

The commercialization of caves drives bats away. Any gating on the cave that prevents access or alters the air flow, temperature, humidity, and amount of light is harmful.


What Is Being Done to Prevent Extinction of the Gray Bat?


The gray bat was added to the U.S. List of Endangered and Threatened Wildlife and Plants on April 28, 1976.


Recovery Plan

The U.S. Fish and Wildlife Service has developed a recovery plan that describes actions needed to help the bat survive.


Habitat Protection

A variety of government and private conservation agencies are all working to preserve gray bats and their caves.


What Can I Do to Help Prevent the Extinction of Species?


Learn more about the gray bat and other endangered and threatened species. Understand how the destruction of habitat leads to loss of endangered and threatened species and our nation's plant and animal diversity. Tell others about what you have learned.



Write to the U.S. Fish and Wildlife Service or your state fish and game agency to learn more about endangered and threatened species.



Join a conservation group; many have local chapters.


Fact Sheet Created September 18, 1997

Gray Bat

Midwest Endangered Species