This Action Plan lists 27 taxa as Extinct, 20 as Critically Endangered, 60 as Endangered, 68 as Vulnerable and 63 as Near Threatened as at 31 December, 2010. The remaining 1028 taxa are deemed to be Least Concern. The Australian list also includes 31 introduced taxa and 151 vagrants. Conservation summaries are presented for all Extinct, threatened and Near Threatened taxa. Of those taxa known to have been present or to have occurred regularly in Australia when Europeans settled in 1788, 2.2% are Extinct and a further 11.8% are considered threatened. Some 5.0% are Near Threatened.
Since the last Action Plan, research and surveys have shown that 61 taxa are less threatened than was thought but a further 26 taxa should have been listed at a higher level. Other differences between the 2000 Action Plan and the present volume can be accounted for by changes to taxonomy (7 taxa) or to more rigorous IUCN criteria that better define the different categories (58 taxa).
Using current knowledge, taxonomy and IUCN criteria, there has been a change in the status of 66 taxa (5.0%) since the last Action Plan. For seven the conservation status can be downlisted as a result of effective conservation management. Abbott’s Booby Papasula abbotti and the Christmas Island Hawk-Owl Ninox natalis shifted from Critically Endangered to Vulnerable as a result action to control invasive ants. The Southern Cassowary Casuarius casuarius johnsonii, Tasmanian Wedge-tailed Eagle Aquilla audax fleayi and Albert’s Lyrebird Menura alberti have all benefited greatly from habitat protection; the first two were Endangered but can now be listed as Vulnerable, the last has been shifted from Vulnerable to Near Threatened after effective protection of Whian Whian State Forest in New South Wales. Numbers of Gouldian Finch Erythrura gouldiae have increased so much in the last decade that they can be moved from Endangered to Near Threatened. The reason is not entirely clear but they are known to have benefited at some sites from better fire management and conservative stocking rates. The population of the seventh taxon, the southern subspecies of Western Corella Cacatua pastinator pastinator has increased so much as a result of effective law enforcement and habitat protection that it has been shifted from Endangered to Least Concern.
However, the status of 39 taxa has been uplisted. This includes four taxa that are now Critically Endangered – three species, the Grey-headed Albatross Thalassarche chrysostoma, the Western Ground Parrot Pezoporus flaviventris and the Regent Honeyeater Anthochaera phrygia, and one subspecies, the Norfolk Island Tasman Parakeet Cyanoramphus cookii cookii. Along with the Orange-bellied Parrot Neophema chrysogaster, the ground parrot and the honeyeater have the potential to be Extinct in the Wild by 2020; all have all suffered rapid declines in their already very small populations. While, for each, a captive population has been established, for only the Orange-bellied Parrot has there been a conscious attempt to capture genetic variability before it is too late.
Most of the additions to the list in 2010 are migratory waders, numbers of which have plummeted, largely due to reclamation or degradation of habitat along their migratory pathways. A more detailed understanding of the taxonomy of grasswrens Amytornis spp., in which similarities in plumage hide deep genetic rifts, has also led to many additional taxa listed, including some that are already Extinct. Most threatened or Extinct taxa continue to be on islands. Here introduced predators, often aided by habitat destruction, have taken a heavy toll, or they could cause losses if they were introduced to places like Heard Island. However, programs to remove or control island predators are having major benefits. At the time of the 2000 Action Plan the problem with an invasion of Christmas Island by Yellow Crazy Ants Anoplolepis gracilipes had just become apparent and many endemic taxa there were deemed Critically Endangered. Rapid action has controlled the ants for the present, though, as it happened, few birds were likely to have been affected in the short–medium term.
On the mainland, land clearance and the resulting habitat fragmentation may continue to cause species declines for decades as biodiversity pays its extinction debt. Grazing by domestic and feral herbivores and changes in fire management are also major threatening processes. However, the rate of land clearing has dropped dramatically and some major fire management programs offer hope for fire-prone landscapes. At sea, all albatross taxa and several petrels continue to be threatened by high rates of mortality associated with fishing, but there has also been substantial progress in developing and implementing mitigation techniques.
Most threatened marine birds frequent the Southern Ocean, particularly around Tasmania. On the mainland, the majority of threatened and Near Threatened taxa occur in the south-east of the continent, particularly west of the Great Dividing Range, with the highest concentration in the Murray mallee and south-western Australia, particularly in the south east of Albany. Australia’s coastlines also support a particularly large number of threatened and Near Threatened taxa because so many shorebird taxa are now listed.