Silence Before the Storm: Song Birds Flee Just Before Disasterous 2014 Tornado Hit

In an accidental discovery, researchers working with migratory birds have concluded avian species can sense warning signals sent out by approaching natural disasters like tornados.

A research team led by UC Berkley scientist Henry Streby was tracking golden-winged Warblers with geo-locator devices in Northern US. Warblers are small song birds which weight about nine grams. They migrate to Colombia in winters and usually return to Appalachian Mountains and Great Lakes for breeding, BBC reported.

In April 2014, one of the worst tornado storms to hit US was brewing. The research team which was studying birds in their breeding area, moved to safer ground for a day in view of the approaching storm which caused massive destruction.

The team returned to find that the birds had gone missing, only to return in a few days. Curious, researchers examined the geo-locators to find that the birds had taken an evasive path to avoid the storm.

"It is the first time we've documented this type of storm avoidance behavior in birds during breeding season, 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," Streby said in a news release.

Researchers established that the birds had left even before conditions in the nesting area changed to warn them. This led to the conclusion that the warblers may have been warned by infrasound tornados produced. Infrasound is not audible to human ear but many species can pick it.

Warblers making evasive maneuvers after settling down to breed also surprised researchers, as the find challenged common perception that birds take such action only during migration.