The causes of decline of birds of eucalypt woodlands: advances in our knowledge over the last 10 years

Abstract

Many species of birds inhabiting the eucalypt woodlands of southern Australia are declining. Although the basic causes are clearing, fragmentation and degradation of these woodlands, several ecological processes are involved. These include: difficulties in dispersing among remnants, interspecific competition, increased nest predation, and decline in key resources, including food. Many bird species declined during the recent long drought in south-eastern Australia. Research over the last decade has strongly emphasised effects at the landscape level. It is now clear that more native vegetation in the landscape leads to more bird species. There is stronger evidence that aggressive and nest-predatory birds contribute to the decline of many woodland birds. Several studies have linked the presence of individual bird species to key habitat features, such as high or low density of trees, shrubs and coarse woody debris. The main priorities for the conservation of woodland birds to reverse these declines are: (1) detailed studies on the population dynamics of a variety of declining woodland birds under different management regimes; (2) experiments that closely monitor the response of woodland birds to manipulation of competitors, predators and habitat features; and (3) broad-scale implementation of management based on science to aim to reverse the fortunes of woodland birds on regional and national scales.