UT Expert Studying Agricultural Impact of Bats

KNOXVILLE — University of Tennessee bat researcher Dr. Gary F. McCracken is part of an effort to gauge the ability of Mexican free-tailed bats to protect Texas crops against insect infestation.

The five-year research project, which is funded by a $2.4 million National Science Foundation grant, is in its second year.

“We have three UT graduate students and one undergraduate participating,” McCracken said.

Mexican free-tailed bats are small mammals that live in Texas from March to October, and then migrate to Mexico for the winter months.

Females primarily migrate to Texas during the birthing season to take advantage of massive numbers of insects. During this time one bat can eat up to two-thirds of its body weight in insects each night.

“The females’ need for food approximately doubles during the birthing season,” McCracken said.

Scientists say bats eat some of the state’s most damaging agricultural pests, those that feed largely on cotton and corn. It is estimated that bats eat enough insect pests to save millions of dollars on pesticide use.

“It’s a double effect in that the bats are saving the crops from being damaged as well as reducing the need for pesticide,” McCracken said.

This spring and summer some of the researchers are tracking the movement of moth caterpillars, a favorite bat food. Other team scientists will determine what percentage of the bat diet is made up of key agricultural pests.
“With ultrasonic detectors, we are able to monitor when the bats are feeding and exactly what they are feeding on,” McCracken said.