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Squirrels eavesdrop on the ordinary bird reader to find out when it's safe enough to be outdoors and look for food.
Researchers have found that a squirrel becomes incredibly alert when it hears the scream of a red-tailed hawk, but it will relax and resume faster if the predator's call is followed immediately by easily flowing tweets of misunderstood birds .
The results described in the journal PLOS One add to the growing body of research that animals make use of all available "public information" when trying to assess threats in their environment.
"Many animals listen to the disturbing calls of other species," says Keith Tervin, a behavioral ecologist at Oberlin College in Ohio. "It's found in various squirrels – earth squirrels, tree squirrels. even in lizards. "
While other researchers focus on how animals adjust to other species for danger warnings, his team focuses on whether animals also monitor their neighbors for signs of safety." I wanted to know if I could to pay attention and other information, "says Emma Lucor, one of Tarwin's former students.
Her idea of exploring how squirrels respond to frivolous bird tweets was taken and expanded by fellow former student Marie Lilly, who did the fieldwork one cold January in Oberlin.
"It definitely looked very ridiculous," says Lilly, who explains that she tuned the audio equipment into several cat litter bins. "And I put those on my bike and basically rode around town looking for squirrels."
After finding a suitable eastern gray squirrel, she would put on her gear and hide behind a bush to perform the experiment.
First, the squirrel will hear the recorded cry of a hawk. Then the squirrel will hear either a few minutes of casual bird talk recorded around a bird feeder, or a few minutes of silence recorded around the same feeder at night.
Using a special application created by a friend of computer science, Lilly records the time the squirrel spends or freezes, eating, running, resting or standing. She was also recording when the squirrel looked up at the sky.
"In the field, I couldn't figure out if their alertness was decreasing or not, because I was just recording their harsh behavior," Lily says.
But after the data had been collected and analyzed, it was evident that hearing the pleasant, calm talk of the birds made the squirrels resume eating faster. "
" When squirrels hear a chatter coming from other birds, that chatter conveys a message or cue that these birds obviously feel pretty safe, says Tarwin. "And squirrels clearly interpret this to mean that the environment is relatively safe."
Daniel Bloomstein, a behavioral ecologist at the University of California, Los Angeles, says this is a great study with compelling results.
"Most of us have thought about the risk side of things, not the security of things," Bloomstein says. "Yet both types of public information are there for you to take, if you know what to find out."
He says researchers have long focused on how individual species respond to other species, but more and more people are thinking of the more complex communication networks in nature, described by Bloomstein as something like "Facebook for birds."
he does some modeling work that suggests hints of bezo other kindness "can be really important in certain situations so that animals can better appreciate the likelihood that they can do things without being killed. “