In his novel The English Patient, Michael Ondaatje mentions “a violent and cold southwesterly known to Berbers as ‘that which plucks the fowls’”.
Wind really can produce this effect, with 19th-century meteorologists recording several instances of chickens stripped of their feathers by tornadoes. Some thought the phenomenon might give valuable clues on the mystery of how fast winds moved inside a tornado.
Prof Elias Loomis set out to investigate, armed with a cannon and a supply of freshly killed chickens. He found that firing birds at a muzzle velocity of 340mph stripped off their feathers, but also reduced the chickens to small fragments. Loomis suspected the gunpowder blast might have been a factor in the shredding, but concluded that the windspeed in a tornado was less than 340mph.
The 20th-century invention of the wind tunnel offered a more scientific way to explore the phenomenon. The meteorologist Bernard Vonnegut – brother of the novelist Kurt – reviewed previous work and observed that it could be affected by “flight moult”, a reaction in which panicking birds shed feathers. This is assumed to be an evolutionary adaptation to ensure predators get only a mouthful of feathers.
Flight moult means that feathers may come out at relatively low wind speeds, leading Vonnegut to conclude that “the plucking phenomenon … is not indicative of winds as intense as might be supposed”.
