Long-nosed Potoroo (southern mainland)  |  

Potorous tridactylus trisulcatus

Status: Vulnerable on the EPBC Act list

The long-nosed potoroo is a compact, medium-sized marsupial with a maximum body and head length of 31–34 cm, a tail length of 23 cm and a weight range of 660–1640 g. The species name ‘tridactylus’ translates to three-toed, although the long-nosed potoroo technically has five toes (the second and third digits are conjoined). The hind limbs are 85–88 cm long and well developed, enabling the animals to hop at great speeds. Their forearms are shorter and muscular with short, strong claws, well adapted to digging. The species has small, rounded ears, large eyes, and, as its name suggests, a long muzzle with a bare tip. The body has two fur layers, a soft, short dark grey fur on the back with coarser hair protruding from it and which can range in colour from yellow-white to brown with a black tip. The underside of the animal is covered in coarse white fur, with a grey base layer. Females have a well-developed pouch that opens anteriorly and contains four mammae. Johnston and Sharman (1976) report a longitudinal gradient in body size in the Tasmanian longnosed potoroo, where smaller animals were observed in the wetter north-west and larger animals in the drier north-east of the island. No such cline was found in either the northern or southern long-nosed potoroo (on the mainland). The southern long-nosed potoroo has a smaller average body size than the northern long-nosed
potoroo and typically weighs under one kilogram (the northern subspecies is heavier and can weigh over one kilogram). The southern long-nosed potoroo also has a longer and thinner muzzle than the northern subspecies. A white tip to the tail is seen more often in southern subpopulations.

Government evidence of impact of climate change:

Expand all Close all
  • Australian Government, Conservation Advice, Potorous tridactylus trisulcatus

    Such catastrophic bushfires are increasingly likely to occur due to climate change (CSIRO Bureau of Meteorology 2015).
    Projections of higher temperatures and reduced mean rainfall for eastern Australia due to climate change suggest that the frequency; intensity and scale of bushfires in the region will increase (CSIRO Bureau of Meteorology 2015).
    Changing weather patterns Increased Timing current Decreased rainfall; increased average temperatures; and temperatures and Confidence observed increased frequency of droughts are increasingly likely to occur altered precipitation due to climate change (CSIRO Bureau of Meteorology 2015).
    Climate Change and fire Ensure that a high proportion of the southern long nosed potoroo habitat is maintained in a long unburnt condition ( 20 years).
    Maintain and protect areas identified as climate change refuges establish corridors to allow movement to modelled suitable habitat under climate change projections.
    Identify high risk subpopulations under climate change and catastrophic depletion scenarios and plan for emergency responses to translocate at risk animals where needed.
    Climate change projections indicate that environmental conditions will facilitate more frequent and intense bushfires in the future (CSIRO 2015).
    The intensity; frequency and scale of catastrophic bushfires will likely increase due to climate change; and future broadscale bushfire events may have an even greater impact on the surviving population than the 2019 2020 bushfires.
    This estimate does not include the potential for future catastrophic bushfires; as may be expected under climate change (CSIRO Bureau of Meteorology 2015).
    Given that bushfires are predicted to increase in frequency and intensity under climate change scenarios (CSIRO Bureau of Meteorology 2015); it is reasonable to predict that the available habitats offering optimum habitat (including those which are 20 years unburnt) will decrease in number and that the scale of future fires may cause similar declines.
    Climate change intensifies the impacts of decreased rainfall; increased average temperatures and increased frequency of droughts (discussed above in Tables 2 and 4).
    The species is unlikely to recover to pre fire population abundance before the next major bushfire event impacting a significant proportion of the species range.
    In Tasmania; Johnson (1995) found that fire triggered a short term increase in fungal fruiting body production (for four months) which increased feeding by another potoroid; Bettongia gaimardi (Tasmanian bettong); a species that has a similar feeding ecology to the long nosed potoroo.
    The southern long nosed potoroo are threatened by habitat loss and fragmentation predation by invasive species; particularly European red foxes and feral cats and inappropriate fire regimes and habitat degradation (due to; for example; forestry activities; livestock; feral herbivores; weeds).
    Where fire is used for managing forest habitats; a frequent or severe burn may impact soil moisture content and directly destroy underground fungi (Claridge et al. 1992 Claridge et al. 1993).
    This may be exacerbated by both increased activity and hunting efficiency of introduced predators in burnt areas after a fire (Hradsky 2020 Leahy et al. 2016 McGregor et al. 2014 Robley et al. 2016).
    Food resources (in particular underground fungi) can substantially decrease post fire (Claridge Trappe 2004 Martin Temple Smith 2012); and this impact is amplified where fire occurs in combination with a history of other environmental disturbance (e.g. logging) (Claridge et al. 1993).
    A short term increase in some underground fungi has been observed post fire (Johnson 1995).
    However; the abundance of some fungi after fire may be offset by increased predation risk in post fire habitats (Robley et al. 2016) and decreased abundance of other fungi (Martin Temple Smith 2012).
    In particular; grassy weeds can Consequence unknown increase fuel load and alter fire regimes (Setterfield et al. 2013 Trend unknown Milberg et al. 1995).
    These altered fire regimes can create Extent across parts of conditions that are detrimental to the maintenance of native the range species and favourable to the establishment and spread of weeds (D Antonio Vitousek 1992).
    The recovery of the forest canopy 15 years post logging and bushfire were presumed to result in an increase in the southern long nosed potoroo; as Lunney et al. (2001) found a 34 increase of the southern long nosed potoroo in the diets of Wild dogs and European red foxes.
    These regimes should include buffers that prevent bushfire or planned burns from impacting habitat and food sources; a post fire introduced predator control program; a post fire population monitoring program; and sufficient funding to facilitate these projects.
    The key threats causing this decline are habitat loss and fragmentation; predation (European red fox) and inappropriate fire regimes.
    A total estimated 57 of the modelled distribution was impacted by fire in the 2019 2020 bushfire season resulting in a population decline of 33 over three generations but as high as 56 decline (Legge et al. 2021).
    No. locations 10 5 10 Bushfires can impact multiple subpopulations at one time and may result in the immediate loss of the southern long nosed potoroo and ongoing declines as a result of post fire predation and loss of food and habitat resources.
    With the increasing frequency of bushfires; the remaining suitable habitat will decline; and so the number of locations in which a single bushfire can rapidly affect all individuals may be lower.
    A further risk to the species occurs post fire as the dense understory vegetation is typically lost; and refuge habitats are not available to protect the species from predation by introduced taxa; predominantly from European red fox; feral and domestic cats and wild and domestic dogs (Hradsky 2020 McHugh et al. 2020 Miritis et al. 2020).
    Percent of the southern long nosed potoroo modelled range of known and likely to occur distribution that was impacted by different fire severities during the 2019 bushfire season (Legge et al. 2021).
    Thus; habitat quality specific to the southern long nosed potoroo has markedly declined post 2019 2020 bushfires and will continue to decline if fire frequency is more than once every 20 years.
    Some habitats may already be experiencing an inter fire interval of fewer than 15 years; and this is expected to increase in the future.
    The reduction exceeds 30 percent due to bushfires and other post fire threatening processes (mostly predation by European red fox).
    Number of locations and declining extent and quality of habitats The Action Plan for Australian Mammals 2012 estimated that there were more than ten locations (Woinarski et al. 2014) based on the key threatening processes (habitat loss; degradation and fragmentation; predation and inappropriate fire regime).
    Here; the number of locations is based on the threatening process of catastrophic bushfires and the compounding co occurring threats of post fire food loss and increased predation by European red fox and feral cats.
    The 2019 2020 bushfires demonstrated that one fire season could impact over half of the range and cause a loss of one third of the population at disparate; geographically separate subpopulations.
    Additionally; bushfires can exacerbate the impacts of drought on the abundance of small and medium sized marsupials (Hale et al. 2016 Crowther et al. 2018).
    Consequence major pattern Drought conditions can act synergistically with bushfires to Trend increasing reduce the abundance of small and medium sized marsupials Extent across the (Hale et al. 2016 Crowther et al. 2018). entire range The southern long nosed potoroo often occurs near watercourses and drainage lines; which may provide shelter during bushfires (Martin Temple Smith 2012).
    Drought is thought to be responsible for the observed declines in the northern long nosed potoroo at Cobaki Lakes; New South Wales; as captures decreased from 20 to 4 individuals within one year; coinciding with increasingly dry conditions (Lewis 2015).
    Prolonged drought is likely to alter forest structures; food webs and key food availability.
    Prolonged drought is likely to alter habitat; forest structures; food webs and key food availability; though how this will impact the southern long nosed potoroo population size; distribution and viability are not well understood.