Birds are able to sense tornadoes from great distances, and flee their nests as one approaches, according to a new discovery.
Golden-winged warblers in eastern Tennessee were studied, and researchers found the animals abandoned their nesting spots one to two days before the arrival of a storm. A massive storm system swept through central and southern regions of the United States in April 2014, just as the birds were breeding in the area. This was the first time avians were seen leaving their nests in large numbers during mating season.
"The warblers in our study flew at least 1,500 kilometers (932 miles) total to avoid a severe weather system. They then came right back home after the storm passed," Henry Streby from the University of California, Berkeley, said.
Birds left their nests while storms were still between 250 and 560 miles away, before air pressure or temperature dropped, or winds became stronger. Meteorologists were making initial predictions as to the direction of the storm front when birds started to leave their nests.
Discovery of the ability to sense tornadoes was made by accident. Researchers wanted to know if the winged creatures were able to carry geolocators, as the animals weigh less than half an ounce. Several of the birds had been equipped with transmitters before the arrival of the springtime storm. Although the warblers had only recently arrived in eastern Tennessee, they fled the oncoming storm, traveling over 900 miles in five days in order to avoid the mighty tempest. Five of the creatures flew toward southern Florida, with one making it all the way to Cuba.
Streby and his team are uncertain exactly how the birds may have known that a storm was headed in their direction. It is possible the animals hay have heard them through infrasound, which can not be detected by human beings.
A total of 35 people were killed during the massive storm studied by the avian researchers. The weather system generated at least 84 tornadoes.
The ability to detect tornadoes well before they strike an area could be useful to the species, as global climate change leads to more frequent, and severe, storms worldwide. This discovery suggests birds may adapt better than expected to global warming.
"On the other hand, this behavior presumably costs the birds some serious energy and time they should be spending on reproducing. The birds' energy-draining journey is just one more pressure human activities are putting on migratory songbirds," Streby said.
Future research will utilize geolocators to track how the birds migrate during winter months.
Study of the ability of detect oncoming tornadoes was detailed in the journal Current Biology.