In a new study, published in this week's issue of the journal Biology Letters, scientists tested whether European birds standing on the side of the road altered their escape distances in response to how fast an approaching car was moving or to road speed limits. (Related: "North American Birds Declining as Threats Mount.")

Study co-author Pierre Legagneux, a biologist at Canada's University of Quebec in Rimouski, said the idea for the experiment occurred to him while he was commuting to his lab in France.

"I found [the commute] very boring so I had to do something while driving, so I started to record birds flying away," Legagneux said.

Using only a stopwatch and a notebook, Legagneux measured the reaction times