Long before people embrace social media and the 24-hour news cycle, some creatures are already tuning into tweets.
A new study in Plos One, by researchers at Oberlin University in Ohio, tests the hypothesis that birds act as informants to the community, essentially posting news from time to time. They find that gray squirrels adjust their alertness levels to the sounds around them, including the chatter of birds.
In other words, when birds call, squirrels listen, and when birds just knock, rodents know they are
To reach this conclusion, an environmental behavior student, Marie Lilly, created various records and went out a bucket full of equipment to gather data on the impact of these tweets on feeding gray squirrels. Lily hid behind trees as she made five sounds for squirrels. To indicate danger, she played the call of a hawk with a red tail, and to show safety, she played either ambient sound or one of three different records of talkative birds. Then, using a specially crafted app, she noted the behavior of squirrels, recording how long a squirrel spent freezing, eating, running, resting, standing or staring at the sky.
However, when analyzing the data collected after 67 experiments – 30 with tweeting bird sounds and 37 with ambient noise – a model emerged. Lily found that squirrels became more alert after hearing the cry of a red-tailed hawk – freezing, running or looking up. But when she whistled at the sound of birds slapping – no matter which of the three records – the squirrels quickly began their regular activities, feeding themselves violently, clearly convinced that the danger had passed through the birds exchanged. Squirrels responded more quickly to the calming of bird song than to ambient noise, indicating that they relied more on inattentive informants to gauge the dangers they were facing than the mere absence of threatening sounds.
In a paper published with Oberlin Professor Keith Tarwin, Lily and her fellow researchers claim that the findings show that animals not only rely on vowel species to transmit hazard information, but also listen closely for safety indications. They note that with the increase in noise pollution levels – which also pose a threat to human health – creatures such as squirrels that rely on news reports of other species will be increasingly threatened because they will miss out on these important tweets.