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Researchers photographed a dehydrated Jacky Winter in South Australian mallee woodland the morning after a 47°C day.
Within 24 hours of a record 49°C in 2019, 29 per cent of studied adults vanished. Scientists presumed them dead.[1]
A national assessment ranks climate change as the biggest threat to Australia’s endangered birds, ahead of invasive species.
Threat load sums the weighted impact scores of every pressure on a group of birds.
The Action Plan for Australian Birds 2020 assesses 188 species or subspecies, about one in six, as nationally threatened.[2][7]
Citizen scientists have monitored 22,000 birds of 37 species at two semi-arid New South Wales sites since 1986.
Survival reached 86 per cent in a mild summer that stayed at or below 38°C.
A hot summer with 30 days above 38°C cut survival to 59 per cent.[1]
Projections show days above 38°C at least doubling at those sites by 2104. Even rapid emissions cuts, holding warming near 1°C, lower annual survival from 63 to 43 per cent. Warming of 3.7°C this century cuts survival to 11 per cent.[1]
Near 35°C, Jacky Winters climb the tallest trees for cooling wind, then pant, which risks fatal dehydration. Above 40°C they shelter in thermal refuges, meaning cool tree-base hollows, for up to eight hours. That halts foraging and drains body mass.[1]
Hollows at tree bases proved significantly cooler than every other measured location. The best hollows occur only in the largest eucalypt mallees. All 41 egg clutches and 21 nestling broods exposed to air above 42°C died.[1]
Drought, fire and heat head the list of individual pressures on threatened birds. Longer or more frequent droughts carry 10.3 per cent of total potential threat impact. Intensified fire carries 10.1 per cent, and rising temperatures and heatwaves carry 7.7 per cent.[2]
Altered fire regimes, meaning shifts in fire frequency, intensity and extent, carry 11.6 per cent of threat load within Australia. Black Summer, the 2019 and 2020 bushfires, worsened the status of 26 species or subspecies, 16 on Kangaroo Island. Researchers also tie fire risk to the end of First Peoples fire management and to flammable exotic grasses.[2][7]
On Kangaroo Island, high-intensity fire burnt over half the habitat of some endemic taxa. Losses ran so deep that some taxa qualified as threatened solely because of the fires. CSIRO researchers urge fire management that protects large trees, because their hollows serve as thermal refuges.[1][2]
Climate change and altered fire regimes jointly supply nearly a third of threat load. They affect 89 per cent of taxa within Australia. Knowledge of how to manage climate threats met just 3 per cent of need in 2020.[2]
Models project 101 terrestrial and inland water bird taxa, meaning species and subspecies, will lose their climate space by 2085. Climate space means the range of climatic conditions that suits a taxon. Birds confined to Cape York, the Wet Tropics, the Top End and the arid zone rank as most vulnerable.[3]
In Queensland’s Wet Tropics, cool-adapted birds retreat uphill as temperatures rise, creating an “escalator to extinction”. Annual surveys at 1,770 sites from 2000 to 2016 recorded rapid declines that tracked model predictions. Fernwren, Mountain Thornbill and Atherton Scrubwren have worsened in status as higher ground runs out.[2][7]
Of the 188 threatened taxa, 23 qualify as Critically Endangered, 76 as Endangered and 89 as Vulnerable. Three birds listed as possibly extinct in 2010 now count as extinct. Climate change lifted its share of total threat load from 17.3 to 20.8 per cent between 2010 and 2020.[2][7]
Fifty-five terrestrial taxa face more frequent or intense fires. Small island taxa rank highest for combined exposure and sensitivity to climate change, followed by marine and shoreline taxa. Yet a substantial share of threatened birds faces neither exposure nor sensitivity.[3]
Sixteen marine bird taxa breed at sites where models predict productivity falling at least 10 per cent. Marine productivity measures how much food the local ocean supplies. A small group of beach-nesting and saltmarsh birds also faces sea-level rise.[3]
A marine heatwave, meaning a prolonged spell of unusually warm seawater, hit eastern Australia in 2023 and 2024. Researchers estimate those heatwaves killed 629,000 seabirds, including two Australian shearwater species. Most birds die at sea, so beach counts capture only a fraction of the toll.[4]
Magpie geese depend on sedge wetlands across tropical northern Australia. Saltwater intrusion from sea-level rise and prolonged flooding after heavier rain could change those sedge plants. Researchers propose buffers at key wetlands to slow the saltwater.[5]
Modelling shows marginal habitat loss in magpie goose food-plant wetlands under 1.4 metres of sea-level rise. Multi-metre rises produce large-scale losses, and the data miss fine-scale intrusion through channels and eroded levees. Researchers urge monitoring of the annual Indigenous harvest, because continued sustainable harvest depends on careful wetland management.[8]
Researchers estimate managing the 396 most exposed or sensitive bird taxa would cost $18.8 million a year. That equals about $47,700 per taxon each year over the next 50 years. Monitoring leads the urgent actions, while refugia (areas that stay habitable) and captive breeding may eventually cost far more.[3]
Eradicating introduced mammals from Macquarie Island cut the total threat load on Australian threatened birds by 5 per cent. Habitat protection and restoration, particularly on islands, and longline fishing controls also delivered measurable benefit. Published guidance on easing heat and drought effects on threatened birds remains virtually absent.[2]
Threatened species funding in the decade to 2020 reached less than one-tenth of the estimated requirement. Taxa with recovery plans matched taxa lacking plans on the share of management need met. Only eight of the federal threatened species strategy’s 22 priority birds rank in the top 20 for threat or need.[2]
Of surveyed Australians, 80 per cent want extinctions avoided. That group prefers managing wild populations where they live over captive breeding. More than 60 per cent of respondents accept conservation managers deciding strategy rather than local communities or the public.[6]
Climate change now outranks every other threat to Australia’s threatened birds. The evidence spans desert mallee, upland rainforest, ocean colonies and tropical wetlands. Heat, drought and fire act on every one of those habitats.
Governance has trailed the science. Funding, knowledge and priority-setting all fell short of the scale of loss. Accountability for that gap rests with the governments that set the strategy and fund the response.
Practical answers exist. Governments can fund monitoring, protect large trees and refuges, restore habitat, control invasive species and plan for climate refugia. Australians have shown support for protecting wild populations where they live, which gives governments a clear mandate.
1. ‘Sad and distressing’: massive numbers of bird deaths in Australian heatwaves reveal a profound loss is looming. CSIRO scientists Janet Gardner and Suzanne Prober report threefold bird mortality in very hot summers, with survival projections to 2104 and evidence on thermal refuges.
2. Monitoring threats to Australian threatened birds: climate change was the biggest threat in 2020 with minimal progress on its management. This peer-reviewed Emu paper by Garnett and colleagues quantifies threat load, research progress and management gaps across all Australian threatened birds.
3. Climate change adaptation strategies for Australian birds. The National Climate Change Adaptation Research Facility report models climate space loss to 2085 and costs adaptation for 396 vulnerable bird taxa.
4. Mortality of shearwaters following a marine heat wave in Australia. The Agreement on the Conservation of Albatrosses and Petrels summarises the Conservation Biology estimate of 629,000 seabird deaths in 2023 and 2024.
5. How will climate change affect plant-herbivore interactions? A tropical waterbird case study. This Emu paper by Traill, Whitehead and Brook outlines how saltwater intrusion and flooding could alter the sedge wetlands that support magpie geese.
6. Social preferences for adaptation measures to conserve Australian birds threatened by climate change. A choice experiment published in Oryx shows Australian public support for managing wild populations in place and for deferring to conservation managers.
7. The Action Plan for Australian Birds 2020 reveals that one in six are nationally threatened. BirdLife DataZone summarises threatened-bird counts, Wet Tropics declines and Black Summer impacts from the Action Plan for Australian Birds 2020.
8. Conservation of north Australian magpie geese Anseranas semipalmata populations under global change. This University of Adelaide research record models sea-level inundation of wetlands and recommends saltwater buffers and monitoring of the Indigenous harvest.
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