Meet ‘Valkyrie’ the ibis who, every day around 7am, likes to walk from her roost at a park on the Redcliffe foreshore for a quick bite from the bins at her favourite fish and chip shop.
“She’s like clockwork,” said University of the Sunshine Coast bird expert Dr Dominique Potvin, who is part of a team of scientists using satellite tags and solar backpacks to identify the ‘happy place’ and habits of Australia’s smelliest and messiest native birds – the white ibis.
Knowing the birds’ favourite haunts – and why they choose them – may be the key to finding more effective ways to discourage them from nesting in areas they are not wanted, according to a new UniSC study published in Urban Ecosystems.
As expected, the findings confirmed that the closer to waste refuge sites, the better, for the bold scavenger who has taken over urban streets, parks and dumps across cities and towns across eastern Australia.
“It seems modifying or reducing access to their preferred habitats could be a tool to managing this important, protected but nuisance species,” said Dr Potvin, a Senior Lecturer in Animal Ecology, who co-authored the paper.
The study found that while the birds like to scavenge at waste management facilities, they do not like to nest there, preferring instead to roost and breed moderately close by.
Ibis and nest numbers were most abundant at sites within 10km of waste management facilities and, while they increased closer to residential or industrial estates, they decreased the further away these areas were from rubbish tips.
“We found proximity to refuge sites is the major driver for where they establish colonies,” Dr Potvin said.
“This highlights the need to focus on both foraging and nesting/roosting sites, and minimising the proximity between them, rather than the current preferred form of solely managing nesting colonies through measures that include egg destruction.”
Nirvana is an ibis island
The research team surveyed 26 colonies and tracked more than 150 birds in the Moreton Bay region for the study, which was funded by the Moreton Bay Council, and used a decade of historical data collected by Council on local populations.
Citizen scientists also contributed, through the Big City Birds app, which gave tagged birds numbers and names, and provided researchers with great insights into their daily habits and likes.
“Like Valkyrie, many tend to follow the same routine. One favourite is Ree Ree, who sets off from her home at Centenary Lakes Park to do a little shopping around the same time most days at the Coles shopping centre at Caboolture,” Dr Potvin said.
“Surprisingly though, considering how many ibis choose to live near people and enjoy the benefits of scavenging their rubbish, our study found they still prefer to nest away in locations with some buffering from people.”
The bird’s ideal place is a water bound island with high tree density. It does not like the trees it roosts in to be too high – less than 10m is best.
It also prefers where there are fewer tree species and may also have a fondness for eucalypts and melaleuca.
The findings suggest there should be a rethink of a growing urban planning trend to place developments near wetlands, according to the research team.
Instead, wetlands may provide an ‘ibis nirvana’ to entice nesting colonies away from urban areas.
Co-author UniSC Associate Professor in Animal Ecology Ben Gilby said this would involve creating or managing wetland areas to maximise suitable nesting conditions, buffering from humans and increased protection from predators.
“As their native inland habitats have declined over the past three decades, they’ve established large permanent and seasonal nesting colonies in urban coastal areas, sometimes numbering hundreds of nests and thousands of individuals,” Dr Gilby said.
“As well as complaints about their noise and odour, and even stealing food from humans, nesting colonies can degrade habitats, smother vegetation, cause erosion, pollute waterways and compete with native species for space.
“Few management interventions have so far been successful, and that’s why this research project to better understand the conditions driving ibis habitat selection is so important.”
Keeping unwanted 'pests' out of the neighbourhood
Lead author Caitlin Willis, who is studying the ibis as part of her UniSC doctoral studies, said the new insights may be useful in guiding urban planning, prioritising interventions for specific sites and identifying future locations where the pest species might colonise.
“To help shift colonies from more urbanised areas and parklands, stakeholders could improve waste management facility policies in ibis reduction plans, especially reducing the amount and accessibility of available onsite refuse,” she said.
“There needs to be careful consideration given to the trees that are being planted in parklands and other urban landscapes, especially if located near foraging grounds.
“To deter large colonies, the solution could be to make green spaces less attractive, with less desirable space, by planting a diverse range of taller trees in low densities within parklands and urban areas.”
Time to dump the bin chicken name – rise oh mighty phoenix, you are a survivor
We've done a disservice to the white ibis by labelling it a "Bin Chicken". It's time to rebadge with a name more befitting to one of Australia's most tenacious native birds. Vote for something that really matters.
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