Bats are among nature's quickest thinkers, capable of making actual split-second decisions.
Using echolocation, or ultrasonic squeaks to locate prey, bats interpret the returning echo to decide when and how to attack, or even to call off the attempt — all within milliseconds, as researchers at the University of Southern Denmark discovered.
"A bat is capable of adjusting its attack until it is approximately 100 milliseconds away from its prey," said Signe Brinkløv, a postdoctoral researcher in the university's biology department.
In experiments conducted both in the wild and in a laboratory, the scientists offered bats prospective prey, and then removed it at the last instant to observe the reaction. They filmed the bats in flight and recorded their echolocation sounds to determine how the bats would respond to the disappearance of their prey.
"As the bats approached their prey, they were continually able to adjust their attack and maybe call off the hunt entirely if we took away the prey," Brinkløv said, noting that they could abort the attempt within milliseconds.
"This tells us that bats can process complex information and make decisions in an extremely short time," she continued. That conscious decision-making should not be confused with reflex actions, which do not require conscious brain activity.
"Sometimes we also see reaction times of only 20 milliseconds in bats, for instance in response to loud sounds, but that is a simple reflex reaction." Bat hunting behaviors, by contrast, are a definite – and remarkably fast – case of decision-making.
The findings are surprising, because up until now, scientists believed bats used a kind of autopilot mode in the last seconds of an attack, which would limit them to a set and unalterable behavior pattern. The rapid decision-making capability is likely an evolved behavior.
"They rely on being able to react extremely quickly when they hunt, so I would think that they've been under strong evolutionary pressure to develop such expedited reactions in order to survive as a species," Brinkløv added.
Brinkløv worked with University of Southern Denmark Professor Annemarie Surlykke and colleagues from the Ludwig-Maximilian University in Munich on the study, which was published in the Proceedings of the National Academies of Science.
