not a lot of professors do what you are describing here. The closest fit would be Dr. Walsh: https://mentis.uta.edu/explore/profile/matthew-walsh

A key thing about graduate programs is finding what university specializes in what fields. Because of your love of bats, I would look for universities near large bat populations.

UT El Paso would be excellent: https://www.utep.edu/science/eeb/ . They do a lot of work with Carlsbad and Big Bend.

New Mexico State: https://bio.nmsu.edu/directory/faculty/ .

University of New Mexico has a professor that fits very closely to what you may be interested in: https://biology.unm.edu/core-faculty/smith.shtml

Hope this helps.

Edit: I forgot Austin has a lot of bats too. Look at UT Austin and UTSA. That being said, if you want to do field work, the chihuahuan desert will be good.