GARDENING BIRDS
The orange-bellied parrot survives on a wing and a prayer as the summer breeding season progresses at its only known nesting site, at Melaleuca in the southwest.
This season only 16 birds have returned to the breeding grounds from interstate, 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 release 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 wildborn population in the breeding grounds.
Ranching ensures 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. In the past, birds reared in captivity and 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 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,” says Holdsworth. “It’ll be a major win for the species and I’ll be very pleased indeed.”
The orange-bellied parrot has suffered a catastrophic population decline in recent years for reasons not fully understood. It travels from southwest Tasmania to winter on the Victorian and South Australian coasts each year. Draining and reclamation of saltmarshes where parrots find winter food is considered a key factor in the decline.