7.30: Scientists study suburban microbats

KERRY O'BRIEN:

The debate on rapid population growth in Australian cities may be primarily about its impact on people, but wild animal species living sometimes unseen in urban environments are also suffering upheaval. In an effort to gauge the effects on one such animal, a group of Melbourne scientists is calling for volunteers to help conduct the world's biggest survey of its type. They'll be searching the suburbs of Melbourne for a number of species of tiny bats, which, anecdotally, are facing a rapid decline. Jeff Waters reports.

JEFF WATERS:

Some bats enjoy a very high profile. Fruit bats, or flying foxes, snooze their days away beside waterways like the Yarra River before heading out to raid backyards. But in metropolitan Melbourne, at least, these plant-eating mammals are greatly outnumbered by their far more secretive insect-eating relatives. Some surveys suggest microbats — that's the type that uses echoes from soundwaves instead of sight and smell to get around — are present in just about every backyard in the city.

DR LINDY LUMSDEN:

You can see his wing quite well like that.

JEFF WATERS:

In her work for Victoria's Department of Sustainability and the Environment, Dr Lindy Lumsden has made a life out of studying microbats.

DR LINDY LUMSDEN:

I started using them for talks and thought, 'Oh, they need to go to the museum at some stage. When they die, in six months time, I'll take them to the museum'. That was 20 years ago and they still haven't died, so they obviously don't want to go to the museum.

JEFF WATERS:

These scientists are looking for a huge number of volunteers to help them find exactly where the wild things are.

DR RODNEY VAN DER REE:

Well, great. Thanks for coming tonight. The aims of the project is to look at the bats across Melbourne and try and understand which species of bats still occur in Melbourne and where they occur.

JEFF WATERS:

The project, to survey a 40km radius from the central business district, is being led by the University of Melbourne's Dr Rodney van der Ree.

DR RODNEY VAN DER REE:

There's been one study that showed that one bat could eat 600 mosquitoes within an hour. So, potentially, they're really, really valuable and they play important roles in the ecosystem.

JEFF WATERS:

The scientists are teaching volunteers who've joined up on the earthwatch.org website. It appears that to catch a bat you have to think like a spider.

DR RODNEY VAN DER REE:

Like that. Under there like that. Yep. So they'll hit the fishing line, slide down the fishing line and then they go into the bag. And once they're in the bag they can sit there for a couple of hours without any problems. And then we come along at regular intervals during the night and take them out. It's an ideal method because there's very little injury to the bats. In fact, I don't know of any injuries that have occurred to bats in heart traps.