Vic: Romance a croak too far for urban frogs - study

AAP General News (Australia)
08-20-2009
Vic: Romance a croak too far for urban frogs - study

By Mariza O'Keefe

MELBOURNE, Aug 20 AAP - Car traffic has been blamed for everything from polluting the
environment to road rage - well now it is being dubbed as a romance killer for urban frogs.

A Melbourne University study has found that the mating calls of male frogs in city
ponds are being drowned out by traffic noise and this is hindering these amphibian romeos'
chances of attracting and breeding with female frogs.

Ecologist Dr Kirsten Parris began her research with the university in 2000 and has
found frogs have disappeared from many of the 104 ponds included in the study and the
number of species in each pond has also reduced.

Its research has found that in some cases male frogs could once be heard by females
800 metres away and can now only be heard within 14 metres thanks to noise pollution.

Of particular concern is the threatened growling grass frog which has all but disappeared
from Melbourne's inner suburbs. Traffic noise is just one thing killing them off.

"The impact of noise comes on top of all these other effects, the other things that
frogs have to deal with in city environments. A lot of their habitat is lost ... (there's)
pollution, introduced predators ... so it's pretty tough for the little guys," Dr Parris
said.

She said female frogs chose their breeding partners based on their mating calls.

"Females generally like evidence of vigour and good health ... females like a guy who
is fit and healthy because he will give her better offspring," she said.

"Male frogs show they are fit and strong by calling fast and loudly and for a long time."

Dr Parris suggests that developers in the inner city should consider creating more
ponds and using barriers such as hedges or dense vegetation that would reduce noise but
still allow frogs to move from pond to pond.

And it is not just female frogs that would miss the baritones of mating male frogs
if they disappeared from the city, Dr Parris suggested.

"I think a lot of people like to hear frogs calling. It's a way to be in touch with
a little bit of nature in the city, where there is not much nature anymore."

AAP mok/gfr/dep

KEYWORD: FROG

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