News

Birds know road speed limits

Crows, house sparrows and other species judge when to flee the asphalt by average traffic rates rather than an oncoming car's speed

By
5:43pm, August 20, 2013

SLOW DOWN  Birds that hang out on roads may rely on the speed  limit to judge when to flee instead of checking how fast an oncoming car is moving, a new study finds.

Highway-savvy birds don’t read road signs but they may pay more attention to speed limits than some human drivers do.

As a car roars toward birds standing on the asphalt, they don’t check the driver’s exact speed when judging how soon to flap out of the way, says behavioral ecologist Pierre Legagneux of the University of Quebec in Rimouski.

Instead, the speed limit on the road, rather than the speed of the approaching vehicle, is a better predictor of how close a car gets before a bird startles into the air, Legagneux and Simon Ducatez of McGill University in Montreal report August 21 in Biology Letters.

Substantial numbers of birds get hit by cars, Legagneux says, so the  new paper gives drivers another reason not to speed. Birds may not expect over-the-limit traffic and may fail to dodge away soon enough.

This article is available only to subscribing members. Join SSP today or Log in.

More from Science News