Changes in the conservation status of Australian birds resulting from differences in taxonomy, knowledge and the definitions of threat Original Research Article

When the conservation status of Australian bird taxa in 1992 was retrospectively reassessed in 2000, the status of nearly 70% had to be changed. About 20% of the differences could be attributed to changes in the predictions of extinction probability. Most differences arose from refinement of ICUN Red List Categories and Criteria. Research showed that some populations were more threatened than realised and a few changes resulted from taxonomic revision. Funds might have been distributed differently had the adjusted analysis been available in 1992. Nevertheless, comparisons between either the original or the revised 1992 list and the 2000 list demonstrate degeneration in overall status of threatened birds in Australia. It is concluded that trends in conservation status are a valid long-term measure of the risk of biodiversity loss. Stabilisation of IUCN Red List definitions should mean that an increasing proportion of the status flux should be attributable to real changes in extinction probability.