With up to 161 km per hour, the Brazilian free-tailed bat can achieve flight speeds faster than those previously documented for any bat or bird, new research has found. Much of the current literature has indicated that birds fly faster and bats are slower and more maneuverable. The new study, published in the journal Royal Society Open Science, demonstrates otherwise.
The study results suggest a reevaluation of the performance abilities and capabilities of bats, said the study’s lead author Gary McCracken, professor at University of Tennessee, Knoxville in the US. Their flight performance has been underappreciated, McCracken added. The researchers conducted the study in southwestern Texas using a novel airplane tracking method.
They caught seven Brazilian free-tailed bats, each weighing 11 to 12 grams. They then attached 0.5-gram radio transmitters to their backs using surgical glue. Until now, the fastest bird records were collected during short flight segments using tracking radar and high-speed video. McCracken and his collaborators used an airplane to follow the complete flight track of the bats. They followed one bat per night.
The researchers’ models indicated that tail winds did not assist the bats’ flight speed. They observed that the bats did exactly what airplanes and birds do, depending on wind conditions. “When they have a headwind, they fly faster. When they have a tailwind, they slow up,” McCracken said. “This is exactly what has been demonstrated in other flight machines, from airplanes to birds,” he noted.