Birds on the brink: 13% of species face extinction
Australia has lost 27 bird species since European settlement, and another 20 are considered at "imminent risk of extinction", according to a global report on the health of the world's birdlife.
Compiled by BirdLife International, the report lists habitat loss, agricultural expansion, climate change and pollution as among the main threats.
Released on Thursday in Canada, the State of the World's Birds report estimates that 1313 of the globe's 10,000-plus bird species are threatened. BirdLife International director of science, information and policy Leon Bennun said this equated to 13 per cent of global bird species, or one in eight.
"This assessment overall shows that birds are not in good shape," Dr Bennun said. "Birds are declining around the globe."
BirdLife Australia head of conservation Samantha Vine said Australia currently had 20 birds on the critically endangered list.
Among them is the orange-bellied parrot, which breeds in Tasmania and travels to south-eastern states in winter; and the regent honeyeater, which has a patchy distribution range stretching from south-east Queensland, through New South Wales to Victoria.
She estimated that on average $380,000 per year was needed for conservation projects to keep each of the critically endangered birds off the extinct list, which includes the Norfolk Island ground dove.
Ms Vine said Australia's birds were struggling, with woodland birds experiencing rapid decline due to land clearing. Invasive species such as introduced rats are also threatening species such as the critcally endangered green parrot on Norfolk Island. Meanwhile, seabirds like albatross and several types of petrels were experiencing high mortality rates due to commercial fishing.
The report estimates that around 160,000 seabirds a year die after being caught in longlines, which can stretch for many kilometres. Birds get caught in the line's hooks and drown. About 70 albatross and petrel species are affected by the tuna fishing technique.
However Ms Vine said there were success stories, such as the education and conservation campaign devised for the hooded plover.
Listed as vulnerable, the Victorian shorebird's population numbers little more than 500. Dogs, people and four-wheel-drives pose the greatest threat to the 20-centimetre bird. But Ms Vine said a program to protect the Victorian nesting and feeding sites had helped chick survival rates increase from 2 per cent to 55 per cent.
Similarly, glossy black cockatoo numbers on Kangaroo Island in South Australia have doubled within 15 years from around 150 birds in 1995. The population boost was due to conservationists putting collars on nesting trees, which stopped the brush-tailed possum from raiding the nests for eggs and chicks.
"Conservation works and it doesn't cost the earth," she said. "It's probably likely that we will be able to down-list [the status of glossy black cockatoos] at the next assessment in 2020."
The international organisation's head of science Stuart Butchart said $US4 billion a year could improve the status of the world's known threatened species and virtually halt human-driven extinctions.
"This is not a bill, it's an investment," he said. "The dividends that we get back are hundreds to a thousand times larger, in terms of the services that nature provides. Things like the food that we eat, purifying the water that we drink and regulating our global climate."
Mr Butchart said a further $US76 billion could help protect and manage all known sites of global conservation significance.