Traffic noise ruins the reproductive life of frogs

According to a new study, traffic noise can ruin the reproductive life of urban frogs by overshadowing the buzzing noise that male frogs make to seduce mates.

A strong cry and momentum is the most valuable asset of male frogs to attract female frogs to their ponds, said Kirsten Parris, an ecologist from Melbourne University.

But traffic noise may have reduced the number of frogs in Australia, the second largest city in Australia since 2000 when Parris began to survey frogs in 100 lakes in the area.

'If at the same time there are many males producing sounds to call, then the one with the most attractive cry will be prioritized by the children,' Parris told the Associated Press reporter. 'If you are a male frog, you must be very aware of the sound asset you have.'

'In general, when a male frog spends a lot of energy on his cries - when his or her voice is loud or fast or extending or at the same time has all the above factors - the frog understands that it is a child. Male is healthy, fit and will choose it to mate, ' she explained.

Parris discovered that the distance that the sound of male frogs could hear clearly was reduced by the impact of traffic noise.

A Growling Grass frog is sitting on a rock in the swamp near Melbourne, Australia. According to a recent study, traffic noise can ruin the reproductive life of urban frogs by overshadowing the booming sound that male frogs make to seduce mates. (Photo: AP / Geoff Heard)

'This makes frogs much more difficult to attract mates and it means the probability of successful reproduction is reduced,' Parris said.

Frogs with deep cries are more disadvantageous because they have to cope with the rumbling sounds of vehicles and other machines, such as air conditioners, she said.

The southern brown tree frog has adapted to this new harsh environment by adding pitch to its cry in the long, noisy traffic areas.

In Melbourne's most noisy places, the common frog's cry can be heard in a radius of more than 19m. With a higher pitched cry, frogs could be heard within 25m.

The popplebonk frog has a distant cry for up to 800m if there is no other noise around.But this gap is reduced to only 14m in areas of high traffic density.

Parris introduced her research to the 10th International Ecological Congress, which took place in Bisbane City, Australia.

Ken Thompson, an ecologist from Sheffield University, Functional Ecology editor described Parris's findings as 'very welcome'.

'There is more and more evidence that noise in urban environments is affecting the activities of many animals,' Thompson said.

Thompson added that another study conducted by his university showed that some birds in the UK had turned to singing at night because their surroundings became too noisy throughout the day.