Out of the 20 species of bat found in Oklahoma, the Mexican free-tailed bat is the state’s favorite. Named the state flying mammal in 2006, this species of bat migrates with the changing season like some birds and insects.

Mexican free-tailed bats have a large wingspan and small bodies. They are grey and have webbing between their feet. They are called free-tailed bats because their tail extends beyond that webbing.

According to the Oklahoma Department of Wildlife Conservation, the state has four maternity caves that are perfect for free-tailed bats to give birth to their pups. They migrate north from south Texas and central Mexico in the spring and summer to do so.

And in the winter, they migrate back south to follow their favorite food source, flying insects like beetles. ODWC manages Sellman Cave where researchers at the University of Oklahoma have been studying the Mexican free-tailed bat’s migration patterns for two years.

Daniel Becker, an assistant professor in the OU School of Biological Sciences, said tracking the bats will answer questions about their migration patterns.

“We’re interested in trying to understand the individual differences in when bats leave, how fast they migrate, where they migrate to, whether that's affected by things like what parasites they're carrying at the time.”

Becker says 40 Mexican free-tailed bats have trackers on them that weigh less than a gram. The trackers are able to pick up when they leave their cave and when they cross state borders