Analysis of the data revealed that the birds took off for Florida several days in advance of a large, severe thunderstorm system that was advancing across the Great Plains.
A new study suggests that these warblers detected the severe weather and got the heck out of the way—an ability never before documented in birds.
The scientists theorize the birds were tipped off by infrasound—a type of low-frequency noise—produced by the storms. Although humans can’t hear infrasound, birds can, and the destructive nature of these storms may make it advantageous for the birds to get out of the way despite the high-energy costs of flight.
“We were completely blown away by this behavior. It shows that the birds can do more than we give them credit for,” said study co-author Gunnar Kramer, a population ecologist at the University of Minnesota in Minneapolis.
Kramer and his colleagues happened upon the discovery by accident, while studying migration patterns of golden-winged warblers.
The songbird spends winters in Central and South America and migrates to the Great Lakes region and the Appalachians to breed and raise young.
To learn more details about this behavior, the team traveled to the Great Lakes and fitted some of the warblers with a small, lightweight geolocator that recorded their exact locations every few minutes, according to the study, published December 18 in the journal Current Biology.
In April 2014, the researchers tracked the birds to the Cumberland Mountains of eastern Tennessee to check on them. But when they arrived, the mountains were silent. Their warblers weren’t there.