By W. Spencer King
Just before tornadoes devastated several central and southern states in April 2014, one group noticed the warning signs and fled to Florida.
Golden-winged warblers left their nests while the storms were more than 250 miles away. The birds breed throughout the Appalachian region and migrate to South America for the winter.
Henry Streby of University of California Berkeley, along with University of Tennessee scientists, tagged the warblers in the Cumberland Mountains of northeast Tennessee for tracking research. They incidentally noticed this unusual out-of-season migration while looking at data following the storms.
Streby told scientific journal Current Biology that the birds were most likely alerted by the low-frequency sounds that tornadoes produce. The sounds, which are below what humans can hear, travel hundreds of miles.
Earthquakes, avalanches and lightning also produce low-frequency sounds, and scientists note that golden-winged warblers are unlikely to be the only species using them as an early warning.