Quantifying knowledge uncertainty in the conservation status of Australian birds

Abstract

Context IUCN Red List assessments have been critical for guiding Australian bird conservation efforts, but for many species data and expertise are limited, and the implications of this uncertainty for status assessment remain poorly quantified. Aims We aimed to quantify knowledge uncertainty for Australia’s threatened and Near Threatened birds and how this varies across threat listing categories and species-specific attributes, such as range size, to determine whether certain characteristics predict lower certainty and reveal systematic biases. Methods We analysed 255 regularly occurring Australian bird taxa, relating expert-assigned certainty ratings (‘high’, ‘medium’, ‘low’) to threat status, population trend, geographic range, population size, number of sub-populations, endemism, and key ecological traits using data from the ’Action Plan for Australian Birds 2020’. Key results Overall, 29% of species (n = 73) had low status certainty, including 48 threatened species. The species’ threat status, population trend, number of mature individuals, and whether a species was endemic were significant predictors of certainty in Red List status. Low certainty was pronounced among Near Threatened species (n = 27), with 63% (n = 17) classified as having low certainty. Conclusions Our research reveals substantial uncertainty in species’ status, even among Australian species considered at immediate risk of extinction. It provides a clear basis for prioritising targeted research toward those species with the lowest certainty. Implications This research provides evidence that a more consistent application of the precautionary principle is needed when considering listing, particularly for those species currently classified as Near Threatened but with high uncertainty.