Study of bat vocalizations shows they are communicating with one another

December 23, 2016 by Bob Yirka, report

Egyptian Fruit Bat (Rousettus aegyptiacus) in flight. Taken at Rothschild Boulevard, Tel Aviv, Israel. Credit: Zoharby/Wikipedia
(—A trio of researchers with Tel Aviv University has found that when Egyptian fruit bats make noises in their colonies, they are actually communicating with one another. In their paper published in the journal Scientific Reports, Yosef Prat, Mor Taub and Yossi Yovel describe their study of 22 captive bats for over two months and what recordings of them revealed.

Scientists have known for some time that most make a lot of noise when they congregate in their colonies—as the researchers report, this is certainly the case for Egyptian fruit bats—when they roost, they get very loud. But until now, it was not known if the bats were simply making random noises or if their calls served a specific purpose.

To learn more about bat vocalizations, the researchers housed a colony for 75 days and recorded bat sounds and movements on video, capturing 15,000 vocalizations in all. They fed the sounds to a voice-recognition system normally used for human voice analysis configured to work on bat sounds and used it to pull out any meaning that might exist. The VR system was able to connect certain sounds made by the bats to certain social situations and interactions that could then be tied to interactions seen in the video. The researchers grouped the sounds into four main groups: arguing over food, mating and sleeping clusters, and differences of opinion regarding how close was too close when hanging around each other in the colony.

The team reports that in many cases, they were able to identify which bat was making a given noise, and sometimes which bat the noisemaker was addressing. They noted also that the bats tended to change their tones when addressing members of the opposite gender. Much of the cacophony in a bat cluster, the researchers suggest, is bats voicing their annoyance with those in very close quarters around them. They also note that their study of bat vocalizing has not concluded—they still want to know if the vocalizations are something they are born with or if they learn as they grow. To find out, the team plans to study bats as they grow—and to learn more about vocalizations outside of the roost, they plan to affix tiny microphones to some of them prior to releasing them back into the wild.

Explore further: Bats found to produce longer and more intense calls when crowded by other bats

More information: Everyday bat vocalizations contain information about emitter, addressee, context, and behavior, Scientific Reports 6, Article number: 39419 (2016) DOI: 10.1038/srep39419 ,

Related Stories

How bats recognize their own 'bat signals'

January 28, 2016

Individual bats emit sonar calls in the dark, using the echo of their signature sounds to identify and target potential prey. But because they travel in large groups, their signals often "jam" each other, a problem resembling ...

Hunting bats rely on 'bag of chips effect'

January 8, 2015

When bats hunt in groups at night, they rely on the sounds of their fellow bats to tip them off on the best places to a grab a good meal. Researchers reporting their findings in the Cell Press journal Current Biology on January ...

Recommended for you

The powerful meteor that no one saw (except satellites)

March 19, 2019

At precisely 11:48 am on December 18, 2018, a large space rock heading straight for Earth at a speed of 19 miles per second exploded into a vast ball of fire as it entered the atmosphere, 15.9 miles above the Bering Sea.

Revealing the rules behind virus scaffold construction

March 19, 2019

A team of researchers including Northwestern Engineering faculty has expanded the understanding of how virus shells self-assemble, an important step toward developing techniques that use viruses as vehicles to deliver targeted ...

OSIRIS-REx reveals asteroid Bennu has big surprises

March 19, 2019

A NASA spacecraft that will return a sample of a near-Earth asteroid named Bennu to Earth in 2023 made the first-ever close-up observations of particle plumes erupting from an asteroid's surface. Bennu also revealed itself ...

Nanoscale Lamb wave-driven motors in nonliquid environments

March 19, 2019

Light driven movement is challenging in nonliquid environments as micro-sized objects can experience strong dry adhesion to contact surfaces and resist movement. In a recent study, Jinsheng Lu and co-workers at the College ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.