January 5, 2018, Australian National University
New research from The Australian National University (ANU) has found genetic evidence that critically endangered swift parrots, which breed all over Tasmania and on predator-free islands, form a single nomadic population at high risk of extinction.
Nomadic swift parrots breed across Tasmania wherever their food is most abundant.
Dr. Dejan Stojanovic from the ANU Fenner School of Environment and Society said DNA collected from nestling swift parrots showed those birds from predator-free Bruny Island and Maria Island were not genetically isolated from populations on mainland Tasmania.
He said the findings supported the need to manage the swift parrot population as a single unit, and that even local threats like deforestation and predatory sugar gliders may impact large proportions of the mobile parrot population.
"We already recognise the importance of predator-free islands as havens for swift parrots, but our findings demonstrate that protecting islands is only part of the solution to saving the parrots," he said.
"This new genetic evidence shows that islands don't support a genetically distinct subpopulation of swift parrots. Birds that nest on islands in one year may move to the Tasmanian mainland the next year, putting them at risk of being eaten by sugar gliders."