The orange-bellied parrot continues to survive on a wing and a prayer as the summer breeding season progresses at its only know nesting site, at Melaleuca in the far south-west.
This season only 16 birds have returned to the breeding grounds from the mainland, 13 males and three females.
Of these, all the females and 10 males were born in the wild and not captive-bred and the other three males are captive-bred birds that survived the winter after being released at Melaleuca.
Long-time orange-bellied parrot researcher Mark Holdsworth says, while this appears to be a very low population, the exciting news is that 15 wild-born juveniles (mostly females) that were captured last summer and kept at the Moonlit Sanctuary in Victoria have now been released back at Melaleuca.
This technique, known as ranching, was first proposed to him four years ago and it has now been implemented for the first time. This has more than doubled the wild-born population in the breeding grounds.
The policy of “ranching” ensures that the birds do not run the risk of being killed on the hazardous migratory journey and females can be guaranteed to breed in the following season. It has been found in the past that birds reared in captivity and then released at Melaleuca, to make the migratory journey, have not survived.
Birds born at Melaleuca are supposed to follow the flock to the mainland, but researchers do not want to take the risk of them not returning.
Although the ranched birds have survived the winter in captivity, the ultimate measure of success of wild ranching will be the production of fledglings by these birds at Melaleuca next month.
“Based on long-term mean brood size of 3.3 for wild-born females, I’m hopeful that these girls will produce at least 46 fledglings,” said Holdsworth. “It’ll be a major win for the species and I’ll be very pleased indeed.”
The migratory orange-bellied parrot has suffered a catastrophic population decline in recent years for reasons that are not fully understood. It travels from south-west Tasmania to wintering grounds along the Victorian and South Australian coasts each year. The draining and reclamation of the coastal saltmarshes where the parrots find winter food is considered to be a primary factor in the species’ decline.
The little green parrot with the splash of orange on its belly is one of only two migratory parrots, both critically endangered. The second is the swift parrot which also only breeds in Tasmania.
Meanwhile, the Department of Primary Industry, Parks, Water and Environment has welcomed the first parrot nestlings across its captive-breeding facilities in Hobart for the current season. A total of 34 breeding pairs have been established at DPIPWE facilities this year, an increase from last year’s 24 pairs. The captive management team in its latest bulletin reported two pairs with nestlings, 18 pairs with eggs and a further 11 pairs preparing to lay eggs.
The increase in captive-breeding pairs this year was made possible by the Tasmanian Government’s $2.5m investment to expend the breeding program in Tasmania.