FRIDAY, 8 NOVEMBER 2013
To answer this question they performed an experiment in France by driving at different speeds (either at the speed limit, over, or under the speed limit) in roads that varied in their speed limits of (20, 50, 90 and 110 km/h).
Whenever a bird flew away from the approaching car the researchers recorded the time from the moment the bird started to fly until the car reached the spot where the bird had been, and calculated the distance at which the bird initiated the flight. They found that birds fly away from the car sooner in roads with higher speed limits.
Surprisingly, the actual speed of the vehicle did not affect their flying distance. The challenge now is to understand how different aspects of the biology of birds, like their mobility or territoriality, may affect how they respond to speed limits.
Written by Ornela De Gasperin. Pierre Legagneux and Simon Ducatez from the University of Quebec and from the university of McGill, respectively, wondered whether birds could use the speed limit from highways as a queue to decide how soon to fly away from a vehicle.