Kangaroos fear sound of own feet

By Jacquie van Santen for ABC Science Online

Farmers may one day blast out a recording of kangaroos thumping their feet to scare them off, new research suggests.

Researchers think using the kangaroo's own alarm signal will be better than existing deterrents, which rely on artificial squeals that pest roos can grow used to.

Dr Helena Bender, who was a PhD student at the University of Melbourne when she did the research, has published her findings in the latest issue of the journal Wildlife Research.

Australia's iconic marsupials are often seen as pests as they can damage crops and property, and compete with livestock for food and water.

But using the sound of foot thumps may be a deterrent.

Kangaroos thump their feet, hitting one on the ground ahead of the other, when they sense danger and take flight.

Often nearby kangaroos will also take flight when they hear the sound.

Until now, the only commercially-available kangaroo deterrent devices have used recordings of non-natural sounds, often a high-pitched squeal.

But studies have found no evidence that these high frequencies are effective for problem species or that they work for anything other than a very short period of time.
Sound recordings

Dr Bender used a recording of an eastern grey kangaroo (Macropus giganteus) foot thump.

She determined its effectiveness compared with a recording of background noise, the sound of rustling eucalypt leaves, over a seven-week period.

She found that just over 60 per cent of kangaroos took flight in response to both the foot thump and the control signals, but more kangaroos took flight in the first three seconds when the foot thump was played.

While the percentage of roos that took flight was almost identical, only the foot thump signal increased the level of alertness of the roos.
Rural benefits

Dr Bender says she hopes her research will benefit rural Australia.

"Reducing the presence of kangaroos in an area should result in a significant decrease in the amount of damage caused, and an increase in harvest yield," she says.

"Moreover, for those kangaroos that remain behind, most of these will be in a state of alertness.

"When kangaroos are alert they cannot feed. This also means less damage to the agricultural property."

She says the foot thump sound could also be used to guide kangaroos away from roadways, thus reducing the number of vehicles damaged by kangaroos and the number of kangaroos injured or killed by vehicles.

http://www.abc.net.au/news/newsitems/200512/s1524251.htm