A new peer-reviewed study has questioned the popular view that logging forests has led to the swift parrot’s collapse, finding that introduced sugar gliders, not native forest harvesting, are the main driver of Tasmania’s most endangered bird toward functional extinction by 2030. That is according to independent researcher Simon Grove, whose paper in Australian Forestry warns that activist campaigns against native forestry are detracting from the only conservation strategy that could save the species.
The swift parrot is native to Tasmania, with no known breeding population on the mainland or elsewhere, leaving an estimated 300 to 500 mature birds uniquely vulnerable to local pressures within a single state. Grove’s paper sets out two opposing accounts of the decline: the forest habitat narrative, which holds that native forest harvesting is the critical mechanism of population loss; and the predation narrative, which attributes the collapse to the killing of nesting females and their broods by sugar gliders, an introduced species absent from Tasmania for most of the parrot’s evolutionary history.
Neither the straightforward forest habitat hypothesis nor a more nuanced version linking sugar glider predation to forest disturbance is well supported by the evidence reviewed in the paper. The predation hypothesis, by contrast, is grounded in empirical observation of nest failures and supported by statistical modelling of breeding-season mortality, with the paper concluding that habitat-focused strategies would do little more than ensure the remaining birds continue to be predated when nesting.
Grove has been blunt about the conservation consequences, arguing that activist efforts directed at native forestry are not merely ineffective but contribute to the very extinction they aim to prevent. “Directing outrage towards the highly regulated forestry sector does nothing,” Grove said.
It comes as Wood Central reported in April that Tasmania’s Forest Practices Authority dismissed Bob Brown Foundation claims of swift parrot nesting within harvest coupe WT003E, with FPA Chief Forest Practices Officer Anne Chuter confirming after an independent ecologist survey on 10 February 2026 that no breeding birds had been observed and that potential habitat had been managed in accordance with the agreed Threatened Species Adviser approach. The Grove paper now provides the peer-reviewed scientific basis for the FPA’s regulatory approach, which the activist campaign against Bunnings supplier Porta has spent six months attempting to discredit.
The implications for Australia’s national conservation effort are direct, with Grove arguing that a strategy focused solely on protecting existing breeding habitat would make no material difference to the species’ fate in the short term and that all-out predation mitigation is the only strategy carrying any prospect of avoiding swift parrot extinction. The Federal Government has pledged $500 million under its Threatened Species Action Plan and committed to preventing further extinctions, but the existing recovery framework concentrates on the breeding range protections Grove’s paper now concludes are inadequate.
The campaign’s focus on forestry has brought the issue to international attention since Leonardo DiCaprio’s 2024 Instagram intervention, when the Hollywood actor cited 750 remaining birds and called on Australian governments to halt logging near nesting sites, and the Bob Brown Foundation secured a Tasmanian Supreme Court injunction in the Huon Valley. The Wilderness Society’s parallel campaign pressuring Bunnings to drop NSW and Tasmanian native hardwoods has run on the same swift parrot habitat argument, citing 68 summer-period acoustic recordings from the Wielangta forest and tying Tasmanian timber supplier Porta to alleged critical swift parrot habitat in coupe WT003E.
Grove’s paper warns that the forestry focus is not merely ineffective but actively detracts from the practical glider-control work the critically endangered species needs to survive, with as few as 300 mature swift parrots remaining across the bird’s sole breeding range in Tasmania.
For more information: Grove, S. J. (2026). What is driving the continued decline of critically endangered swift parrots? A re-examination of the research papers. Australian Forestry, 1–34. DOI: 10.1080/00049158.2026.2634414
