Researchers "Translate" Bat Talk. Turns Out, They Argue—A Lot
A machine learning algorithm helped decode the squeaks Egyptian fruit bats make
in their roost, revealing that they "speak" to one another as individuals
Plenty of animals communicate with one another, at least in a general
way—wolves howl to each other, birds sing and dance to attract mates and big
cats mark their territory with urine. But researchers at Tel Aviv University
recently discovered that when at least one species communicates, it gets very
specific. Egyptian fruit bats, it turns out, aren’t just making high pitched
squeals when they gather together in their roosts. They’re communicating
specific problems, reports Bob Yirka at Phys.org.
According to Ramin Skibba at Nature, neuroecologist Yossi Yovel and his
colleagues recorded a group of 22 Egyptian fruit bats, Rousettus aegyptiacus,
for 75 days. Using a modified machine learning algorithm originally designed
for recognizing human voices, they fed 15,000 calls into the software. They
then analyzed the corresponding video to see if they could match the calls to
certain activities.
They found that the bat noises are not just random, as previously thought,
reports Skibba. They were able to classify 60 percent of the calls into four
categories. One of the call types indicates the bats are arguing about food.
Another indicates a dispute about their positions within the sleeping cluster.
A third call is reserved for males making unwanted mating advances and the
fourth happens when a bat argues with another bat sitting too close. In fact,
the bats make slightly different versions of the calls when speaking to
different individuals within the group, similar to a human using a different
tone of voice when talking to different people. Skibba points out that besides
humans, only dolphins and a handful of other species are known to address
individuals rather than making broad communication sounds. The research appears
in the journal Scientific Reports.
“We have shown that a big bulk of bat vocalizations that previously were
thought to all mean the same thing, something like ‘get out of here!’ actually
contain a lot of information,” Yovel tells Nicola Davis at The Guardian. By
looking even more carefully at stresses and patterns, Yovel says, researchers
may be able to tease out even more subtleties in the bat calls.
This isn't the end of the research, Yirka reports. Yovel and his team want to
investigate whether bats are born knowing this “language” or if they learn it
over time while living in their colonies. They also want to know if the bats
use similar communication outside the roost. To understand that, they will
attach microphones to some bats and release them into the wild.
Kate Jones, professor of ecology and biodiversity at University College,
London, tells Davis that the research is very interesting. “It is like a
Rosetta stone to getting into [the bats’] social behaviors. I really like the
fact that they have managed to decode some of this vocalization and there is
much more information in these signals than we thought,” she says. She says
that it might even be possible to use similar techniques to begin understanding
nuanced communications in other species as well.
http://www.smithsonianmag.com/smart-news/researchers-translate-bat-talk-and-they-argue-lot-180961564/?utm_source=&utm_medium=smithsoniandaily&utm_campaign=email&spMailingID=27416568&spUserID=NzQwNDU4MTU4MjQS1&spJobID=944862046&spReportId=OTQ0ODYyMDQ2S0
Jerry Atkinson.
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