MIAMI (AFP) ― Birds appear to be able to sense a coming storm and fly away before it hits, according to research out on golden-winged warblers in the United States.

These tiny, delicate birds weigh just 9 grams, or about as much as a palmful of coins, and yet somehow they knew that a massive storm system ― including tornadoes and high winds ― was on its way one to two days in advance.

They fled their breeding grounds in the mountains of eastern Tennessee just before the big storm system swept through the central and southern United States in late April 2014.

The storm caused at least 84 tornadoes and killed 35 people.

“It is the first time we’ve documented this type of storm avoidance behavior in birds during breeding season,” said ecologist Henry Streby at the University of California, Berkeley.

“We know that birds can alter their route to avoid things during regular migration, but it hadn’t been shown until our study that they would leave once the migration is over and they’d established their breeding territory to escape severe weather,” he said.

When the birds flew off, the storm was still hundreds of kilometers away, so there would have been few detectable changes in atmospheric pressure, temperature and wind speed.