Smooth, manmade surfaces create a 'blind spot' for bats using echolocation

September 07, 2017

Bats are well known for their sophisticated use of echolocation to navigate through areas riddled with obstacles, but now a new study reveals that this useful ability is hindered in the face of smooth vertical surfaces - those that are particularly likely to be manmade. The results help explain why injured or dead bats are often found near buildings, and underscore the negative impact of human development on wildlife. To navigate through the dark, bats rely heavily on echolocation, where they emit high-frequency sounds and use the returning echoes to detect, classify, and localize objects in their environment. However, several observations of bats colliding with smooth vertical surfaces (such as glass windows) suggest that bats have problems recognizing them. To explore this issue in greater detail, Stefan Greif and colleagues monitored greater mouse-eared bats (Myotis myotis) as they flew through a continuous, rectangular flight tunnel in the dark. In the corner of the dark tunnel, the researchers placed a metal plate either vertically or horizontally. In natural habitats, smooth vertical surfaces are rare, yet bats encounter smooth horizontal surfaces in the form of water. Of 21 individual bats, 19 collided with the vertical plate at least once (on average 23% of passes) but never with the horizontal plate. The researchers found that when the bats collided with the vertical plate, they were producing fewer calls, spending less time in front of the plate, approaching the plate at a more acute angle, and had higher flight speeds relative to the bats that avoided collision. The authors report similar findings in field experiments outside of caves of three different bat species. These results are discussed in a Perspective by Peter Stilz.

American Association for the Advancement of Science

Related Bats Articles from Brightsurf:

These masked singers are bats
Bats wear face masks, too. Bat researchers got lucky, observing wrinkle-faced bats in a lek, and copulating, for the first time.

Why do bats fly into walls?
Bats sometimes collide with large walls even though they detect these walls with their sonar system.

Vampire bats social distance when they get sick
A new paper in Behavioral Ecology finds that wild vampire bats that are sick spend less time near others from their community, which slows how quickly a disease will spread.

Why doesn't Ebola cause disease in bats, as it does in people?
A new study by researchers from The University of Texas Medical Branch at Galveston uncovered new information on why the Ebola virus can live within bats without causing them harm, while the same virus wreaks deadly havoc to people.

The genetic basis of bats' superpowers revealed
First six reference-quality bat genomes released and analysed

Bats offer clues to treating COVID-19
Bats carry many viruses, including COVID-19, without becoming ill. Biologists at the University of Rochester are studying the immune system of bats to find potential ways to ''mimic'' that system in humans.

A new social role for echolocation in bats that hunt together
To find prey in the dark, bats use echolocation. Some species, like Molossus molossus, may also search within hearing distance of their echolocating group members, sharing information about where food patches are located.

Coronaviruses and bats have been evolving together for millions of years
Scientists compared the different kinds of coronaviruses living in 36 bat species from the western Indian Ocean and nearby areas of Africa.

Bats depend on conspecifics when hunting above farmland
Common noctules -- one of the largest bat species native to Germany -- are searching for their fellows during their hunt for insects above farmland.

Tiny insects become 'visible' to bats when they swarm
Small insects that would normally be undetectable to bats using echolocation suddenly become detectable when they occur in large swarms.

Read More: Bats News and Bats Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to