Common Name
greater bonneted bat

Pronunciation: you-mops per-oh-tis

The greater bonneted bat is the largest bat in the U.S., with a wingspan approaching two feet. It is found in California, Nevada, Arizona, Texas, Mexico, and as far south as Argentina, though it is rarely encountered in large numbers. Almost nothing is known about the behavior or status of western mastiff bats. Because they roost in cliff-face crevices and feed high above the ground, they are rarely seen and approach the ground only at a few select drinking sites.

This bat is severely limited by available drinking water. Its long, narrow wings preclude it from drinking at ponds less than 100 feet long. Apparently, due in large part to the loss of large natural springs, western mastiff bats are no longer found in many previously occupied areas and may be endangered, though past and present observations are too few to determine their status.

Approximate Range