9 Mar 2010

Love them or loathe them the Australian white ibis seems a permanent fixture on the Sydney urban landscape. UTS Department of Environmental Sciences doctoral candidate has spent the last four years engrossed in their world. His research yielded some incredible data.

In reality there has been a massive decline in ibis numbers in their traditional areas and they are now found in every major Australian city, cleverly adapting to the ways of urban living, helping themselves to lunch at landfill sites and generally getting up people's noses.

"Yes, unfortunately the white ibis has taken on a sort of 'pest status' in a number of urban areas," said , who has given a final doctoral seminar detailing his research into the urban ecology of this native bird.

"They are accused of everything from destroying habitats, spreading disease and being a hazard to air traffic safety. The media attention is usually negative because, to top it off, they have a low aesthetic appeal. They can be noisy and smelly."

Driven by drought, and with a loss of wetland habitat compounded by increasing regulation of water flows in inland river systems, these environmental refugees have joined the original seven pairs translocated to Taronga Zoo in the 1970s.

Andrew's investigation aimed to provide baseline data that could be used by authorities given the task of dealing with the fallout from the establishment of roosting and breeding colonies in parks and gardens.

"There was a decrease in egg and clutch size and there were less hatchlings. But these urban birds increased their breeding period and had higher fledgling success enabling them to almost double their reproductive productivity," Andrew said.

From the recovery of 93 of the banded birds and analysis of data collected from previous state and national ibis surveys Andrew also concluded that the birds are highly mobile, moving between landfill sites, flying up to 25km per day with breeding and population dynamics that are much more complicated than previously thought. The large scale movement of juvenile ibis from Victoria to Papua New Guinea has been recorded.

It appears that approximately 60per cent of birds die in their first year, mainly due to starvation. It's possible that having grown up at the landfill the young birds may not know how to feed traditionally. Urban ibis management just got a whole lot trickier.

"It has enormous management implications.  It means we can't view east coast ibis populations in isolation. It also means that urban landfills play a crucial role in sustaining the abundance of birds in urban environments," Andrew said.

Environment Co-ordinator for Bankstown Council, Helene Forsythe, believes that Andrew's research will help the council manage negative community perceptions about the white ibis.

"We don't want public opinion to drive wildlife management. Now I can put forward a more precautionary perspective so that Bankstown can maintain viable breeding colonies," she said.

"We were the first council to have a management plan with the National Parks and Wildlife Service (NPWS). We need more knowledge and data, so more funding is needed to expand on this very valuable research."

Andrew's project was sponsored by NPWS, the Royal Zoological Society of NSW and the UTS Science Centre for Environmental Sustainability.

A Journal paper, co-authored with Andrew's supervisor Dr Ursula Munro, has been accepted by Emu-Austral Ornithology and will be published later in 2010.

Contact: Terry Clinton Ph: +61 2 9514 1623