New York: Birds have the ability to sense the arrival of severe storms well in advance to ensure they are safe, a US study has suggested.
They listen to infrasound, associated with the severe weather, at a level well below the range of human hearing to pack up their belongings and flee, the researchers suggested.
The researchers discovered that the golden-winged warblers took off from their breeding ground in the mountains of eastern Tennessee well before severe storms swept through the central and southern US in April 2014.
They found that all the warblers travelled 1,500 km in five days to avoid the storms that caused at least 84 tornadoes and killed 35 people.
"The most curious finding is that the birds left long before the storm arrived," said Henry Streby of the University of California.
"At the same time that meteorologists on The Weather Channel were telling us this storm was headed in our direction, the birds were apparently already packing their bags and evacuating the area," Streby added. The birds fled from their breeding territories more than 24 hours before the storm arrived.
"Meteorologists and physicists have known for decades that tornadic storms make very strong infrasound that can travel thousands of kilometres from the storm," Streby added.
While the birds might pick up on some other cue, he added, the infrasound from severe storms travels at exactly the same frequency the birds are most sensitive to hearing.
"This behaviour presumably costs the birds some serious energy and time they should be spending on reproducing," the authors noted.
The study appeared in the journal Current Biology.