Bandicoots thriving on Melbourne's urban fringe: Deakin study

Scientists from Deakin's Centre for Integrative Ecology set up traps to monitor numbers of southern brown bandicoots in parts of residential and farm land between Koo Wee Rup and Bunyip, south-east of Melbourne.

Lead researcher Sarah Maclagan, a Deakin School of Life and Environmental Sciences PhD candidate, said the area had once been the largest swamp in Victoria, before being drained to form agricultural land in the 1870s.

"There's only about 5 per cent of the natural vegetation left, and most of this is concentrated in narrow linear strips along drainage channels, roads and railway lines," Ms Maclagan said.

"They're also full of weeds, but these strips seem to be really important habitat for bandicoots."

Ms Maclagan said she was amazed to find a higher density of bandicoots within these small areas than in protected native habitat in the nearby Royal Botanic Gardens at Cranbourne and on Quail Island Nature Conservation Reserve.

"We also looked at the body condition of the 'urban' animals and found that this was the same as those captured in the reserves," she said.

"Their breeding rate was steady too, and two thirds of the animals could be classified as 'residents' of the novel sites, meaning they were observed there across multiple seasons and weren’t just passing through.

"So it's a weird situation where you've got weed infested roadsides harbouring an endangered mammal."

Ms Maclagan said this habitat was what ecologists called a "novel ecosystem".

"Basically it means an ecosystem that has been so greatly modified by humans that there's no practical way for it to return to what it was," she said.

"The commonly held theory in conservation is that ecosystems altered by humans offer a lower quality habitat for native animals.

"But what this study is showing is that they can actually be helpful in supporting endangered species like the southern brown bandicoot.

"This may seem counterintuitive. For example predators like foxes and feral cats are largely eliminated from the nature reserves, yet are abundant in the urban area. The nature reserves also have much more intact native vegetation.

"But we found lots of bandicoot nests in blackberry bushes, which we would normally see as a problematic invasive species. These offer good protection from predators, and may also attract insects that bandicoots like to eat.

"Another factor might be the new food sources available in the neighbouring residential areas. I've spoken to lots of local landholders who have bandicoots regularly coming to eat food intended for pets or domestic animals (like pigs and chickens). They're very opportunistic eaters."

Southern brown bandicoots are a small to medium sized marsupial, weighing up to a kilo and a half. They're ground dwelling, keep their young in a pouch and when conditions are good they can breed rapidly with the shortest gestational period of any mammal - just 12.5 days.

Ms Maclagan said the Deakin study showed novel habitats could sometimes provide valuable conservation opportunities for certain species.

"We should take advantage of these opportunities whenever they arise, and not just assume that wildlife can't do well in habitats altered by humans," she said.

"This is especially important with increasing urbanisation globally, including Melbourne's urban sprawl."