Settlement and Swift Parrots — historic and ongoing habitat loss for a critically endangered species (1788–2016)

Abstract

The Swift Parrot, Lathamus discolor White, 1790, was among the first of Australia's birds to be scientifically described and illustrated following European settlement in 1788. Within 60 years of settlement, key habitat throughout the species' range was being lost. A unique compilation of historical and recent information on Swift Parrot habitat loss demonstrates how past events have rendered this species Critically Endangered. A crucial aspect of the loss of habitat is the speed and spatial extent over which it occurred. The most extensive loss happened during colonial times however, losses continue to this day due to various government land management policies and practices. Consequently, the Swift Parrot remains the subject of an ongoing national recovery program and its future is far from secure.

Documenting demise? Sixteen years observing the Swift Parrot Lathamus discolor in suburban Hobart, Tasmania

“…The low numbers of fledglings observed were also consistent with high rates of predation by Sugar Gliders (Stojanovic et al 2014(Stojanovic et al , 2017Heinsohn et al 2015), and the frequent collisions with man-made structures clearly add an additional source of mortality that is capable of exacerbating population decline. In addition to predation and collisions, ongoing loss of both nesting and foraging habitat through industrial forestry, harvesting of firewood, and inappropriate fire regimes, as well as agricultural, residential and other developments, is thought to adversely affect the Parrot (Hingston & Piech 2011a;Saunders & Tzaros 2011;Allchin et al 2013;Saunders & Russell 2016;Stojanovic et al 2016;Webb et al 2019). Indeed, there is evidence that habitat loss is exacerbating the problem of predation by Sugar Gliders (Stojanovic et al 2014).…”

“…Together with the absence of long-term trends in the mean date of 13 August for the first detection each year in Hobart from 1974 to 2002 (Beaumont et al 2006), the lack of long-term trends in the mean date of 10 August for the first observation during this study suggests that this variable is not undergoing any directional change. However, because the spatial distribution of the Parrots varies among years, and I sampled only a fraction of their potential range, it is possible that the absence of longterm changes in seasonal activity patterns at my study site were not reflective of other parts of Tasmania (Saunders & Russell 2016).…”