Gray Myotis (Myotis grisescens)
The gray bat is highly social, strictly cave-dwelling bat that lives in the southeastern United States because of this, their distribution tends to be patchy. The caves they roost and hibernate in are limestone caves. They are never found within man-made structures. They are found in cave regions of Arkansas, Missouri, Tennessee, Alabama, and Kentucky. Occasionally, they can be found in specific areas of Florida, Georgia, Indiana, Illinois, Oklahoma, Mississippi, and Virginia.
Size and Color
After molting, gray bats are a distinct dark gray color, but in between molting, they bleach to a russet brown color. They range in length from 3 to 4 inches long and they tend to weigh between 7 and 16 grams. They are the largest member of the Myotis genus.
Diet and Behavior
They are incredibly selective about their selection of hibernation and summer caves. Their hibernation caves need to maintain a temperature between 42 and 52 degrees. In the summer, they select caves that maintain a temperature between 57 and 77 degrees. Because they are so selective, it has been seen that the entire population of gray bats hibernate in 8 or 9 different caves spread between Tennessee, Missouri, Kentucky, Alabama, and Arkansas. For example, the hibernation cave in Arkansas is estimated to host a quarter of a million gray bats.
These insectivores hunt mayflies, moths, dragonflies, and other aquatic insects over water sources that are located near their roosting sites. They mate in the fall once they enter their hibernation caves and they do not become pregnant until they reach their summer caves.
Pregnant females separate into maternity caves while all other individuals inhabit bachelor caves. The females do not become sexually mature until they reach 2 years of age. They give birth to a single pup in June and the pup is independent by August.