ABOVE: © ISTOCK.COM, ALECOWENEVANS
Eastern gray squirrels (Sciurus carolinensis) and some species of songbirds are both preyed on by red-tailed hawks. A study released September 4 in PLOS ONE suggests that squirrels modify their vigilance behavior based on “bird chatter,” the chirps that birds make while at rest, in addition to bird alarm calls.
A team led by biologist Keith Tarvin at Oberlin College played recordings of hawk calls to 67 gray squirrels found in parks and residential areas in Oberlin, Ohio. They followed the hawk tape with playback of either bird chatter or ambient noise without bird chatter. The squirrels that heard bird sounds after the hawk call showed a faster drop off in vigilance behaviors, such as freezing in place or fleeing, and they also looked upward less, The Guardian reports.
“When squirrels are hearing chatter coming from other birds, that chatter conveys a message or a cue ...
