Bats have been found to cock their heads to the side to hear better in the same way dogs, cats and humans do – but for the purpose of killing more effectively. Species that use echolocation to hunt were found to wiggle their ears and tilt their heads to enhance their hearing in the critical moments of a hunt.
Johns Hopkins scientist Melville J. Wohlgemuth had noticed the bats he was working with cocked their heads to the side: Its an adorable behaviour, he said.
I was curious about the purpose. I wanted to know when bats were doing this and why. It seemed to occur as bats were targeting prey, and that turns out to be the case.
Wohlgemuth and colleagues looked at the ear and head movements of the big brown bat, a common species that hunts in both open and cluttered spaces, meaning it requires good control over sonar signal production and echolocation to relevant signals from prey.
The team measured in precise detail the head and ear movements as the bat tracked and killed prey from a platform.
Findings, published in PLOS Biology, showed the bat would temporarily synchronise its sonar vocalisations with head and ear movements to enhance target detection and work out exactly where it was.
Head movements took place when the insect moved erratically or changed direction. Ear movements took place as the prey got closer.
Researchers believe the coordination of vocalisations and head and ear movements are integral to high resolution acoustic imaging. They also say it has implications for other species, shedding light on parallels between spatial perception by echolocation and vision.
Study co-author Cynthia F Moss said: By studying these movements we as humans can get insight into how movement helps animals sense their environment.
