Roar of traffic drowns out frogs' love croaks

Traffic noise could be ruining the sex lives of urban frogs by drowning out the seductive croaks of amorous males, according to an Australian researcher.

A well-projected and energetic croak is the male frog's most important asset in the quest to attract mates to his pond, said a Melbourne University ecologist, Kirsten Parris. But competition from traffic noise in Melbourne could be why frog numbers have declined in Australia's second-largest city since her survey of more than 100 ponds began in 2000, she said. "If there are a number of different males calling, the one that sounds the best often gets the girl," said Dr Parris. "You have to be pretty clear about your assets if you're a male frog." Dr Parris found the distance at which a frog suitor can be heard by a potential mate is slashed by city noise.