Little songbirds, known as GOLDEN-WINGED WARBLERS fled their nesting grounds in Tennessee up to two days before the arrival of a fierce storm system that unleashed 84 tornadoes in southern US states in April. The researchers said the little birds were apparently alerted to the danger by sounds at frequencies below the range of human hearing. Songbirds have an inbuilt early warning alert for nature’s furies. The storm killed 35 people, wrecked many homes, toppled trees and tossed vehicles around like toys, but the Warblers were long gone, flying up to 930 miles to avoid the storm, and reaching points as far away as Florida and Cuba, the researchers said. Local weather conditions were normal, when the birds took flight from their breeding ground in the Cumberland Mountains of eastern Tennessee, with no significant changes in factors like barometric pressure, temperature or wind speeds. And the storm, already spawning tornadoes, was still hundreds of miles away. Said wildlife biologist David Andersen of the US Geological Survey and the University of Minnesota, “We hypothesize that the birds were detecting infrasound from tornadoes that were already occurring, when the storm was still quite distant from our study site.”
Infrasound is below the normal limits of human hearing, but some animals can hear it. The warblers came right back home after the storm passed.
The GOLDEN-WINGED WARBLER is a New World warbler. The male has a black throat patch, suggestive of the throat patch of a Chickadee , black ear-patch bordered in white, yellow crown and wing patch. Females feature a similar colouration pattern, but the black is replaced with light grey. In both sexes, extensive white on the tail, is conspicuous from below. The bill is long and slender. These warblers are migratory, breeding in eastern N. America and wintering in southern Central America and the neighbouring regions in Columbia, Venezuela and Ecuador. They lay 3-6 eggs in a highly-concealed cup nest on the ground or low in a bush. They feed on insects and spiders and leaf-roller caterpillars. The song is highly variable, but is often heard as a trilled bzzzzzzz buzz buzz buzz. The call is a Buzzy chip or zip.
GOLDEN-WINGED WARBLERS are the first birds seen migrating during the breeding season to AVOID TORNADIC STORMS. So, you might want to be careful about who you call BIRDBRAIN. Some of our feathered friends exhibit powers of perceptions that put humans to shame.