Koala (combined populations of Queensland, New South Wales and the Australian Capital Territory)  |  

Climate change drivers (e.g.; drought and rising temperatures) have also resulted in a reduction in climatically suitable habitat (Adams Hosking et al. 2011).
Forecasting models predict that a large area of koala habitat may be lost; accompanied by a large reduction in the koala population; under 2070 climate change projections (Adams Hosking et al. 2011 Runge et al. 2021b).
Modelling of future climate suitable koala distribution indicates a further contraction of 17 to 78 percent by 2030 from the 2011 baseline as a direct result of climate change (Adams Hosking et al. 2011 Adams Hosking et al. 2016).
The bioregions predicted to be most heavily impacted by climate change included the Mulga Lands (100 percent of climatically suitable koala habitat lost by 2030); the Desert Uplands (100 percent loss by 2030) and the Central Mackay Coast (57 to percent loss by 2030).
Modelling of koala habitat in New South Wales suggests climate suitable habitat will contract by 8 to 19 percent by 2030 from the 2011 baseline as a direct result of climate change (Adams Hosking et al. 2011 Adams Hosking et al. 2016).
Extinction risk is predicted to be greater in western NSW than in the east under future scenarios of climate and land use change (Santika et al. 2014).
Modelling suggests climatically suitable koala habitat in the Australian Capital Territory will contract by 10 percent by 2030 from the 2011 baseline as a direct result of climate change (Adams Hosking et al. 2011 Adams Hosking et al. 2016).
Important populations are defined as those that are valued for cultural; social; and economic reasons as well as for the species conservation. i) For conservation of the listed koala; among other reasons; it will be imperative to maintain populations that have the potential to act as source populations to adjacent areas of suitable; or potentially suitable; habitat exist in areas of climatically suitable refugia during periods of environmental stress including droughts; heatwaves; and long term climate change are genetically diverse are disease free and or exhibit low rates of infection with important pathogens contain genes which may confer adaptation to current and future environmental stressors are geographical or environmental outliers within the species range. ii) Populations are also valued for social; cultural or economic reasons; and may or may not; overlap with populations listed above.
Climate sensitive populations Koalas at the western edge of their range are being impacted by shifts in rainfall patterns and increasing frequency of drought and heat stress resulting directly from climate change (Adams Hosking et al. 2011 Davies et al. 2013 Runge et al. 2021b).
Threats The koala is threatened by wide scale climate change drivers which include the increased frequency and intensity of drought and high temperatures; the increasing prevalence of weather conditions which promote bushfire; and a shrinking climatically suitable area (Adams Hosking et al. 2011 McAlpine et al. 2015 Runge et al. 2021a).
For example; habitat clearance and climate change drivers are associated with increased levels of physiological stress in wild koala populations (Narayan 2019).
Table 1 Threats impacting the koala Threat Status and severity a Evidence Climate change driven processes and drivers Loss of climatically suitable Status current and future Areas that are climatically suitable habitat Confidence known for koalas are contracting (Adams Hosking et al. 2011).
Climate change Consequence severe predictions indicate drier; warmer Trend increasing conditions across the koala s range.
Extent across the entire range Current and future climate change projections indicate a progressive eastward and southwards contraction in the koala s suitable climate envelope and consequent suitable habitat (Adams Hosking et al. 2011).
The effects of climate change may play out through increased mortality associated with heat wave events and droughts; declines in reproduction rates associated with changes in food quality and availability; changes to movement patterns; exposure to diseases and other factors; as well as effects of climate change on fire regimes (see below for further details on these mechanisms).
Cumulative frequency of droughts across the koala range are projected to increase by 30 by 2100 under RCP6.0 (the climate pathway we are on) (NOAA 2021).
Due to Trend increasing climate change; average Extent across the entire range temperatures across the koala s range will continue to increase across all seasons resulting in an increased frequency and intensity of heat stress days and heat wave episodes (BoM 2021a).
The fire season length is increasing and the number of catastrophic fire days will increase in the future by an estimated 15 70 by 2050 (Climate Council 2019).
These include high frequency fire; high severity fire; shifts in fire season; biodiversity loss; declining ecological mechanisms; shifts in biotic interactions including reproduction and fire predator interactions; fire drought interactions; fire fragmentation interactions which can be amplified by land clearing and logging; fire climate feedback (see above) (Bradshaw et al. 2018 Leavesley et al. 2020).
These inputs will provide information for a strategic and coordinated approach to koala conservation; now and into the near future using predictive climate change impacts.
Trend contracting Contracting due to climate related threats and habitat loss and land clearance.
New England North West Climate Change.
During the 2019 2020 bushfire season an estimated 9 percent ( 36;800 km2) of the koala s distribution was impacted by fire (DAWE 2021a).
Both these bioregions were impacted by bushfire in the 2019 2020 bushfires.
Four bioregions were impacted by fire South East Queensland (2 percent burnt); Central MacKay Coast (2 percent); Brigalow Belt South (1 percent burnt); and New England Tablelands (1 percent).
Predicted changes in the near (2030) and more distant (2070) future include increased maximum temperatures; reduced minimum temperatures; more extremely hot days (where maximum temperature 35oC); shifting rainfall patterns; and an increase in average fire weather days.
Since this framework was developed; this bioregion has been impacted by bushfire (see below).
The bioregions most heavily impacted by fire included the South East Corner (52 percent burnt); the Sydney Basin (30 percent burnt) and NSW North Coast (30 percent burnt).
Koalas have displayed nuanced responses to fire with significant declines in numbers following high severity fire but little change in occupancy or density following low severity fire (NSW Government 2021a).
Further research is required to understand how fire impacted koalas across the different bioregions.
Droughts also interact with threats posed by inappropriate fire regimes.
Increased Status historical current future During the summer of 2019 2020; intensity frequency of Confidence known 3.5 million ha of koala habitat burnt bushfire across Queensland; New South Wales Consequence severe and the Australian Capital Territory Trend increasing (DAWE 2021a).
While koala s have returned to bushfire impacted locations it is likely to take many years before populations are fully re established.
A broad range of fire related threats exist.
Number of 10 Geographically isolated populations subpopulations exist throughout the koala s range due to habitat fragmentation resulting from large scale land clearing; drought and bushfire impacts.
The high intensity fire impacts are likely to have the worst impact in poorly connected subpopulations (n 5).
While fire was considered as a threat in the elicitation exercise of Adams Hosking et al. (2016); fires of the scale of 2019 20 were not anticipated in estimating declines that were likely to occur after (Hosking; Kavanagh; Lawler; Lunney; Melzer; Menkhorst; Moore pers comm April 2021).
In particular; shifts in summer temperatures; humidity and water availability pose a significant threat to the koala as a result of acute physiological stress during heatwaves; compounded by drought (Runge et al. 2021a).
These declines have been driven by habitat loss; temperature increase and drought (Lunney et al. 2014 Santika et al. 2015).
Predicted changes in the near (2030) and more distant (2070) future include increased maximum temperatures; reduced minimum temperatures; more extremely hot days (where maximum temperature 35oC); shifting rainfall patterns; and an increase in average fire weather days.
Under the EPBC Act; the following factors and any other relevant factors may be considered when identifying habitat that is critical to the survival of a species (a) whether the habitat is used during periods of stress (examples flood; drought or fire) (b) whether the habitat is used to meet essential life cycle requirements (examples foraging; breeding; nesting; roosting; social behaviour patterns or seed dispersal processes) (c) the extent to which the habitat is used by important populations (d) whether the habitat is necessary to maintain genetic diversity and long term evolutionary development (e) whether the habitat is necessary for use as corridors to allow the species to move freely between sites used to meet essential life cycle requirements (f) whether the habitat is necessary to ensure the long term future of the species or ecological community through reintroduction or re colonisation (g) any other way in which habitat may be critical to the survival of a listed threatened species or a listed threatened ecological community.
Increased Status historical; current and future Over the last 21 years; South East intensity frequency of Confidence known Australia has experienced two of its drought worst droughts in the historical Consequence severe record the Millennium Drought Trend increasing (2000 2009) and the Big Dry (2017 Extent across part of its range 2019).
The frequency of severe and extreme droughts (Drought Severity Index 1.6) will increase from 2.7 to 19.5 .
This is an increase from the currently observed frequency of drought every 5 years and severe drought every 30 years.
Number of 10 Geographically isolated populations subpopulations exist throughout the koala s range due to habitat fragmentation resulting from large scale land clearing; drought and bushfire impacts.
Koala habitat is patchy and fragmented and increasingly prone to threats from drought resulting in multiple subpopulations (n 3).

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