Traffic noise could be ruining sex lives of frogs

Aug 21, 2009 By ROD McGUIRK , Associated Press Writer
In this undated photo, a Growling Grass Frog sits on a rock in swampy lands near Melbourne, Australia. Traffic noise could be ruining the sex lives of urban frogs by drowning out the seductive croaks of amorous males, an Australian researcher said Friday, Aug. 21, 2009. (AP Photo/Geoff Heard)

(AP) -- Traffic noise could be ruining the sex lives of urban frogs by drowning out the seductive croaks of amorous males, an Australian researcher said Friday.

A well-projected and energetic croak is the male frog's most important asset in the quest to attract mates to his , Melbourne University ecologist Kirsten Parris said.

But competition from traffic noise in Melbourne could be a reason 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," Parris told The Associated Press. "You have to be pretty clear about your assets if you're a male frog."

"Generally, if he's putting a lot of energy into calling - if he's calling loudly or quickly or for a long time or all those things combined - it shows he's fit and strong and generally those things tend to correlate with female choice," she added.

Parris found the distance at which a frog suitor can be heard by a potential mate is slashed by city noise.

"This makes it much harder for frogs to attract mates and this could then mean that their breeding success is reduced," Parris said.

Frog species with low-pitched croaks are most disadvantaged because they are competing against the low-pitched rumble of traffic and machinery such as air conditioners, she said.

The southern brown tree has adapted by raising the pitch of its croak in areas where there is traffic din, she found.

In the noisiest parts of Melbourne, the frog's usual pitch cannot be heard by other frogs beyond 21 yards (19 meters). At the higher pitch, the croaks carry an additional 16 feet (5 meters).

The popplebonk frog's call can be heard by females from 875 yards (800 meters) without background noise. That range shrinks to only 46 feet (14 meters) near busy roads.

Parris presented her research on Thursday to the 10th International Ecology Congress in the eastern city of Brisbane.

Ken Thompson, a University of Sheffield ecologist who edits the British journal, Functional Ecology, described Parris' findings of reduced mating because of traffic noise as "highly plausible."

"There is accumulating evidence that noise in urban habitats is having an effect on the behavior of animals," Thompson said.

He said his own university's research found British birds were singing at night because their habitats had become too noisy during the day.

©2009 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Explore further: 221 new species described by the California Academy of Sciences in 2014

add to favorites email to friend print save as pdf

Related Stories

Scientists discover ultrasonic communication among frogs

May 11, 2009

(PhysOrg.com) -- UCLA scientists report for the first time on the only known frog species that can communicate using purely ultrasonic calls, whose frequencies are too high to be heard by humans. Known as ...

Frog muscles survive big sleep

May 10, 2007

A rare Australian frog that burrows underground for a summer siesta resurfaces more than nine months later in just as good a shape as before its rest, according to UQ research.

Frogs flown from Montserrat to flee deadly fungus

May 09, 2009

(AP) -- Scientists are airlifting dozens of one of the world's largest frogs off of Montserrat island to save them from a deadly fungus devastating their dwindling habitat. The dense forest of this tiny British ...

Recommended for you

Ninety-eight new beetle species discovered in Indonesia

3 hours ago

Ninety-eight new species of the beetle genus Trigonopterus have been described from Java, Bali and other Indonesian islands. Museum scientists from Germany and their local counterparts used an innovative approa ...

A vegetarian carnivorous plant

Dec 19, 2014

Carnivorous plants catch and digest tiny animals in order and derive benefits for their nutrition. Interestingly the trend towards vegetarianism seems to overcome carnivorous plants as well. The aquatic carnivorous bladderwort, ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Nederluv
not rated yet Aug 21, 2009
Don't worry, electric cars are on their way!

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.