Sydney, Jul 26 (IANS): Automated acoustic sensors are helping dramatically slash the time and cost of following bird calls to monitor the effects of climate change.

Until recently, ecologists wanting to identify the presence or absence of wildlife have had to spend days in isolated regions, tracking bird calls in all kinds of weather.

A Queensland University of Technology team, working with its Institute for Sustainable Resources, developed automated acoustic sensors, placed in the bush to record environmental sounds which are then transmitted to an online digital library.

But ecologists still faced the prospect of sifting through many hours of recordings and isolating bird calls from other sounds like wind and rain - until now, according to a Queensland release.

"The software filters through the audio and isolates the parts where it can identify potential species amid the cacophony," said Queensland doctoral researcher Jason Wimmer.

"People are much better at identifying species than computers, so we leave the final analysis up to the human brain. We post the audio segments online and ask the birdwatching community to have a go at telling us what they are."

Early trials have had fantastic results. Roughly twice as many species have been detected using this approach than traditional surveys with people in the field.

In one recent experiment, while trained observers were able to detect 35 bird species using traditional bird survey methods, the acoustic sensors and software employed by Wimmer picked up 61 birds in the same area.

"We can record the data using inexpensive MP3 recorders or we can upload it via the 3G
network," Wimmer said.