SYDNEY: An innovative Australian project is using a network of mobile phones to monitor a population of rare birds and send the data back to researchers.
“Sound provides the heartbeat of the environment,” said Richard Mason, lead researcher behind the project at the Queensland University of Technology in Brisbane. “Like listening to someone’s heartbeat, it reveals a lot of information about [ecosystem] health.”
As Brisbane Airport builds its second runway, Mason’s team are analysing the environmental impact of the construction on endangered Lewin’s rails and a number of other wetland birds. Lewin’s rails (Lewinia pectoralis) are found in Australia, Indonesia and Papua New Guinea. They are a shy, well-camouflaged, ground-dwelling species, making them difficult to monitor by sight alone.
Previously, sound recordings were made by customised hardware or data loggers, said Mason. But these typically require mains power, frequently replaced batteries, or very large solar panels. Alternatively, researchers would go into the field to make manual recordings – but traditional surveying methods are expensive and time-consuming.
“Previously when biologists wanted to take a census or survey bird populations like this, they had to rise at 3:00am to be on site before dawn and continue to make frequent labour-intensive site visits throughout the day,” he said. “These repeated visits raise the risk of disturbing the very creatures under investigation, altering their behaviour in response to the presence of biologists and disturbing the habitat.”
Instead, the scientists have set up a network of 3G mobile phones over a one kilometre by thirty metre rectangular area to act as sensors and audio recording devices. The mobiles transfer the recordings of birdsong back to the lab via the 3G radio network, there they are stored, analysed and filtered to glean valuable data. Though the phones also record airport and construction noise, the researchers are able to filter this out.
The handsets used in this project are powered by ordinary lithium batteries, which get charged by a small, 15-watt solar panel, and they can even record two hours of sound a day for up to a week with no direct sunlight. Like many modern phones that come equipped with an operating system, they are programmable and can be remotely controlled via a web-based interface using the mobile’s 3G capabilities.
Monitoring ecological change
The project has been running for eight months so far. QUT ecologist and co-worker Jennifer Gibson has already used that data to better understand the hours of activity that the rails keep.
Mason and his team will detail the method and some early results in June at the International Conference on Distributed Computing in Sensor Systems in Santorini, Greece.
Stuart Gage, an entomologist at Michigan University in East Lansing, U.S., described the project as “a very innovative research activity … [which] has great potential for monitoring ecological change”. Gage himself has used remote audio sensors to monitor ecosystems but not with mobile phones.
The project could be used to monitor the vocalisations of many other species too, said Mason. “In future, that could mean smart phones are not just for the birds, but also frogs, bats and other wild creatures.” Audio recordings might, for example, help researchers study human impact on the environment and change across the seasons as well as population sizes and distributions, he said.