Jakarta Globe - AFP, Dec 19, 2014
Miami. Birds appear to be able to sense a coming storm and fly away before it hits, according to research out Thursday on golden-winged warblers in the United States.
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| A male golden-winged warbler carrying a light-level geolocator on his back and identification bands on his legs, is seen in the Cumberland Mountains of Tennessee, US, in this undated handout photo provided by Gunnar Kramer. (Reuters Photo/Gunnar Kramer) |
Miami. Birds appear to be able to sense a coming storm and fly away before it hits, according to research out Thursday on golden-winged warblers in the United States.
These tiny,
delicate birds weigh just nine 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
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 miles away, so there would have
been few detectable changes in atmospheric pressure, temperature and wind
speed.
“The
warblers in our study flew at least 1,500 kilometers total to avoid a severe
weather system. They then came right back home after the storm passed.”
Scientists
think that this sixth sense that birds possess has to do with their ability to
hear sounds that humans cannot.
Birds and
some other animals have been shown to hear infrasounds, which are acoustic
waves that occur at frequencies below 20 hertz.
Events like
winds blowing, ocean waves crashing and volcanoes erupting at faraway distances
can create infrasounds that birds may be able to sense, even when the events
themselves are thousands of kilometers away.
Tornadoes
are also known to produce strong infrasound.
“There’s
growing research that shows that tornadoes are becoming more common and severe
with climate change, so evasive actions like the ones the warbler took might
become more necessary,” said Streby.
The
findings are published in the journal Current Biology.
Agence France-Presse
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