They also occupy more lightly timbered habitats, including farmland and urban areas, especially during winter when part of the upland population moves to lower elevations (Chambers 1995), also extending into regrowth forests and drier forest types such as box-ironbark (Loyn 1985). Gang-gang Cockatoos occur in a wide range of forests from the coasts through foothill forests and associated gullies to montane forests and sub-alpine woodlands, favouring mature forests for breeding (Loyn 1985). (2021) best estimated a global rate of decline of 30-49% over the past three generations (27 years Bird et al. Combining these analyses and incorporating temporal and spatial uncertainties, Cameron et al. In the Australian Capital Territory, reporting rates were three times higher in 1987–1989 than the fairly stable reporting rate since (Canberra Ornithologists Group 2020). However, the decline in 2-ha 20-min surveys from 1999–2019 (8,987 individuals 267,885 surveys) was only 15% (BirdLife Australia 2020). 2002), including a decline of 44% in New South Wales (Barrett et al. This follows a significant decline of 22% between 1977–19–2001 (Barrett et al. Reporting rates from 500-m radius area searches (20,094 individuals 328,201 surveys), arguably the most reliable of the available survey methods for the species, declined by 69% from 1999–2019. Apart from fire impacts, trend data are not entirely consistent. It is estimated that the 2019–2020 fire season reduced the carrying capacity of 40% of grid cells by half and resulted in 10% mortality (Cameron et al. Combining these measures and uncertainty creates a likely population estimate of between 17,600 and 35,200 mature individuals, with a most likely figure (the midpoint) of 25,300. The density applied assumes an average density of 3.1 birds/km 2, that the 2019–2020 fire season reduced the carrying capacity of 40% of grid cells by half and resulted in 10% mortality (Cameron et al. (2021), the smallest being the number of 2x2 km squares for which there are records since 1990, the latter being an arbitrary value of nearly double this to account for incomplete survey effort of potentially suitable habitat. Population justification The estimate used here is the product of three predicted AOO measures (spanning 22,700-40,000 km 2) from Cameron et al.

For these reasons the species is assessed as Vulnerable.

Justification of Red List category Despite this species having a large range, reporting rates and the impacts of recent fires indicate rapid population declines in the last three generations, and this decline is likely to continue with climate change projections.

Gang gang cockatoo lifespan