THREATENED SPECIES SCIENTIFIC COMMITTEE Established under the Environment Protection and Biodiversity Conservation Act 1999

The Minister’s delegate approved this Conservation Advice on 16/12/2016.

Conservation Advice Bettongia tropica

northern bettong

Conservation Status Bettongia tropica (northern bettong) is listed as Endangered under the Environment Protection and Biodiversity Conservation Act 1999 (Cwlth) (EPBC Act) effective from the 16 July 2001. The species was eligible for listing under the EPBC Act as on 16 July 2000 it was listed as Endangered under Schedule 1 of the preceding Act, the Endangered Species Protection Act 1992 (Cwlth).

Species can also be listed as threatened under state and territory legislation. For information on the current listing status of this species under relevant state or territory legislation, see http://www.environment.gov.au/cgi-bin/sprat/public/sprat.pl

The main factors causing the species to be eligible for listing in the Endangered category are a restricted extent of occurrence, severely fragmented distribution, and a decline in habitat extent and quality.

Information in this Conservation Advice, particularly the sections on the description, distribution and threats, draws on the recent assessment of Woinarski et al. (2014). Any substantive additional sources of information have been cited within the Conservation Advice.

Description The northern bettong is a small potoroid (Macropodoidea) with an adult weight of 1 - 1.5 kg, a body length of 300 - 380 mm and a tail length of 290 - 360 mm. The species has pale grey fur with a cream underbelly (DEHP 2013). Distinctive features include: a short black crest of fur on the upper-distal part of the tail; very short fore-limbs which are held close to the body while moving; long nails on the hands (used for digging); delicate hind legs; and a rounded back and low head while hopping. There are no distinct morphological differences between sexes (Dennis 2001).

Distribution

The northern bettong is endemic to north-eastern Queensland. It has a small, fragmented distribution and only occurs within a thin strip of sclerophyll forest along the western margin of rainforest in the ecotone between savanna woodland and rainforest.

The species is known to occur in the following locations:

• The western side of Lamb Range (including Davies Creek, Emu Creek and Tinaro subpopulations): substantial number of individuals over a broad area (density of 4−7 individuals/km 2). • The western edge of the Mt Carbine Tableland: small and restricted subpopulation with low density of individuals (Dennis 2001; Winter et al., 2008). Extant subpopulations may occur at Mt Windsor Tableland and Coane Range (Paluma) (Dennis 2001; Winter et al., 2008; Bateman et al., 2012b; Mulder et al., 2012).

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Individuals were previously recorded in the Australian Wildlife Conservancy’s Mount Zero– Taravale wildlife sanctuary, but have not been detected in the area for many years.

Northern bettongs have undergone a large contraction in their range (Dennis 2001). They no longer occur in two of their previously known locations, Dawson Valley and the greater Ravenshoe area (Dennis 2001; Winter et al., 2008). The species distribution appears to be limited by the availability of food resources and vegetation associations which are heavily influenced by fire (Dennis 2001).

Due to historical isolation, there is a genetic split between northern and southern subpopulations (Mt Carbine and Coane Range). The two divergent clades are both present in the Lamb Range subpopulation indicating an expansion from the northern and southern subpopulations to this site (Pope et al., 2000).

Relevant Biology/Ecology Habitat of the northern bettong includes a range of eucalypt forest types, from tall and wet forest dominated by Eucalyptus grandis (flooded gum) and tall forest dominated by Eucalyptus resinifera (red mahogany), abutting the rainforest, to medium height and drier woodlands dominated by Corymbia citriodora (lemon scented gum) and Corymbia platyphylla (poplar gum) (Johnson& McIlwee 1997; Dennis 2001; Winter et al., 2008).

The species is solitary and nocturnal. Individuals have three or four nest sites which they use randomly, sleeping in well-concealed nest sites during the day (Dennis 2001).

Northern bettongs are heavily dependent on truffles (specialised fungi) as a food source during the wetter parts of the year. Truffles, belonging to about 36 species of fungus, generally comprise about 45 percent of the diet of northern bettongs. The subterranean stem bases from Alloteropsis semialata (cockatoo grass) and Hypoxis species (lilies) comprise 10 - 35 percent of the species’ diet (McIlwee 1994; Johnson & McIlwee 1997). During the late part of the dry season when truffle availability is low, northern bettongs are particularly dependent on the swollen underground tubers of cockatoo grass (Abell et al., 2006). Herbs, invertebrates and seeds comprise a small proportion (approximately 10 percent) of the northern bettong diet (McIlwee 1994; Johnson & McIlwee 1997).

Home ranges are typically 50 - 70 ha, but may be as large as 120 ha (Winter et al., 2008). Vernes (2003) found that males have a larger home range than females, 72 ± 10.9 ha versus 49 ± 8.4 ha, respectfully. However, both genders had a high mean rate of movement while foraging. Ranges overlapped for individuals, both between and within sexes.

At the site studied by Vernes (2000), small-scale, low intensity fire had no impact on the location or use of individuals’ home ranges. Both during and after a fire, individuals remained within the limits of their movements prior to the fire and there was no direct or indirect mortality of bettongs associated with fire. Individuals sought shelter under boulders which are common at the site; it is noted that the impacts of fire may be different elsewhere, particularly at sites on rhyolite (much of the Coane Range population) where boulders are rare. Despite the lack of broad-scale changes to movements associated with fire, there were clear changes in the fine scale movements and foraging patterns of bettongs immediately after a fire. Search effort for truffles becomes focussed, the level of foraging success is higher and the foraging path more sinuous in recently burnt areas compared to unburnt areas (Vernes 2000).

Northern bettongs reproduce year-round; typically, a single young is born and remains in pouch for about 100 days (Dennis 2001). Under optimal conditions, a female can produce up to three young per year (Dennis 2001; Winter et al., 2008). However, studies in the wild suggest that sub-adult recruitment rates are probably low (Vernes 2000, 2003). The species becomes sexually mature at about nine to 11 months and longevity is seven years (Jones et al., 2009). Generation length is assumed to be approximately three years.

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Threats

The northern bettong’s restricted geographical range and small, isolated subpopulations make them extremely susceptible to stochastic extinction events, inbreeding depression or predation from a few individual introduced predators (Dennis 2001). Only one subpopulation (Lamb Range) appears large enough to be self sustaining (Dennis 2001, 2012).

Table 1 – Threats impacting the northern bettong in order of severity of current risk, based on available evidence. Threat factor Threat type Evidence base and status Fire Low fire known The eucalypt forest and woodland preferred by northern frequency and current bettongs supports a higher biomass of truffles, cockatoo intensity grass and lilies than wetter forest types (Abell et al., 2006). Open forest and woodland habitats require fire to maintain food resources, particularly cockatoo grass and lilies, in the understorey. A lack of fire (low fire frequency and/or intensity) allows rainforest species to dominate the understorey, shading out the groundcover resources required by the northern bettong (Abell et al., 2006). Up to 70 % of tall forest types have undergone sufficient alteration, due to rainforest invasion in the last 200 years, making areas of habitat unsuitable (or marginal) for the northern bettong (Harrington & Sanderson 1994). Marginalisation of northern bettong habitat due to alteration of vegetation structure appears to be occurring in wetter habitat at higher altitudes of the species range (Abell et al., 2006). Invasive species (including threats from grazing, trampling, predation) Competition with known Evidence demonstrating the impact of pigs on northern pigs ( Sus scrofa ) current bettongs is limited. However, pigs may threaten northern bettongs through competition for food resources and alteration of habitat. Pigs are known to selectively graze and uproot cockatoo grass, often causing a reduction in the abundance of these resources (Crowley et al., 2004). A large proportion (up to 47.4%) of sites in bettong habitat has been affected by pig rooting activity (Laurance 1996; Laurance & Harrington 1997). Predation by cats suspected Cats are considered to be a threat to northern bettongs (Felis catus ) current based on their impact to related species. However, the impact of cats on northern bettongs has not been demonstrated. Predation by potential Foxes are considered to be a significant future threat to foxes ( Vulpes future northern bettongs based on the impact to related species vulpes ) (DEHP 2013; Dennis 2001, 2012). Foxes are occasionally observed in the range of northern bettongs; however, they are unlikely to become established there. Habitat loss, disturbance and modifications Inappropriate suspected Only a small proportion of the northern bettong’s range is land use current located within National Parks. Much of its range occurs in state forest and the Wet Tropics World Heritage Area, which is mixed-use and allows some development.

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Logging suspected Habitat change and clearing associated with past logging past are likely to have contributed to past declines of northern bettong (Bateman & Johnson 2011; Dennis 2012). In 2001, timber extraction was identified as a threat to northern bettongs located within state forest (Dennis 2001). Impacts from domestic species Livestock grazing suspected Cockatoo grass abundance is threatened by livestock past grazing due to its low seed bank and early wet season flowering; grazing in the early wet season can reduce inflorescence production for two years (Crowley & Garnett 2001). Livestock grazing may have previously influenced changes to habitat structure, causing a decline in preferred habitat and food resources for the northern bettong (Bateman & Johnson 2011; Dennis 2001, 2012). Climate change Drought known The availability of truffles is strongly associated with current rainfall, with truffle abundance decreasing with reduced rainfall. Decreased abundance of truffles during drought conditions appears to have caused a contraction of the northern bettong’s range from south to north, and from west to east (Abell et al., 2006). Drought may have been the cause for the decline of the Coane Range population (Bateman 2010; Bateman et al., 2012 a, b). Small isolated subpopulations are particularly vulnerable to drought (Abell et al., 2006). Further contraction of the species range and associated population declines are likely to continue as drought frequency and intensity continues as a result of climate change (Abell et al., 2006).

Conservation Actions

Conservation and Management priorities Fire

o Provide maps of known occurrences of northern bettongs to local and state Rural Fire Services, and seek inclusion of mitigation measures in bush fire risk management plan/s, risk registers and/or operation maps. o Implement an appropriate fire management regime in areas of known subpopulations to maintain suitable habitat by thinning woody plants and restoring the grassy understorey. Fire frequency and intensity must be based on sound scientific evidence. A fire management program must have demonstrated funding to ensure that post-fire monitoring and control actions, such as invasive predator control, occur. Invasive species (including threats from grazing, trampling, predation)

o Develop and implement appropriate control methods for pigs, foxes and cats in areas of known bettong subpopulations, and monitor the subsequent response of bettong populations to determine the effectiveness of the control measures.

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Impacts of domestic species

o Identify whether livestock grazing currently occurs within areas of known subpopulations. If so, install fencing to prevent livestock from accessing known northern bettong sites, particularly in the early wet season. Breeding and other ex situ conservation actions

o Maintain a captive breeding program to permit translocations. o Translocate individuals to appropriate sites within the former range. o Translocate individuals to known sites to restore or supplement small subpopulations. Stakeholder Engagement

o Liaise with organisations which have undertaken, or are currently undertaking surveys/monitoring of northern bettongs, including: James Cook University, WWF- Australia, CSIRO, the Australian Wildlife Conservancy and local conservation organisations (e.g. Kuranda Envirocare). o Liaise with state co-regulators to ensure appropriate management activities/programs are undertaken within areas of Queensland Government jurisdiction to manage threats to known subpopulations of northern bettongs (e.g. feral pigs). This includes the Queensland Government Department of Environment and Heritage Protection, and the Queensland Parks and Wildlife Service (Queensland Government Department of National Parks, Sport and Racing). o Erect appropriate conservation signage in areas of known subpopulations to educate the public about northern bettongs.

Survey and Monitoring priorities • Undertake post-fire monitoring to assess the regeneration of cockatoo grass and truffle species • Regularly monitor known subpopulations to more precisely assess population size, distribution, and population trends. • Survey areas identified as ‘likely habitat’ or ‘potentially suitable habitat’ for the northern bettong, to locate any additional subpopulations. • Monitor the progress of conservation actions, including the effectiveness of management actions, and adapt them if necessary.

Information and research priorities • Develop and implement cost-effective monitoring protocols to enhance current monitoring programs. • Develop methods to restore degraded habitat due to woody thickening and rainforest invasion (e.g. fire and mechanical thinning). • Undertake fire trials to assess the response of northern bettongs, invasive species, cockatoo grass and truffle species to different fire regimes, and to identify the optimal fire regime for conserving northern bettongs. • Investigate options for linking and enhancing current subpopulations and/or establishing additional populations (e.g. translocation).

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References cited in the advice

Abell, S. E., Gadek, P. A., Pearce, C. A. & Congdon, B. C. (2006). Seasonal resource availability and use by an endangered tropical mycophagous marsupial. Biological Conservation 132 , 533-540.

Bateman, B. (2010). Beyond simple means: integrating extreme events and biotic interactions in species distribution models. Conservation implications for the Northern Bettong (Bettongia tropica ) under climate change. PhD Thesis, James Cook University, Townsville.

Bateman B. L. & Johnson C. N. (2011). The influences of climate, habitat and fire on the distribution of cockatoo grass ( Alloteropsis semialata ) (Poaceae) in the Wet Tropics of northern Australia. Australian Journal of Botany 59 , 315-323.

Bateman, B., VanDerWal, J. & Johnson, C. N. (2012a). Nice weather for bettongs: using weather events, not climate means, in species distribution models. Ecography 35 , 306– 314 .

Bateman, B., VanDerWal, J., Williams S. E. & Johnson, C. N. (2012b). Biotic interactions influence the projected distribution of a specialist mammal under climate change. Diversity and Distributions 18 , 861–872.

Crowley, G. M. & Garnett, S. T. (2001). Growth, seed production and effect of defoliation in an early flowering perennial grass, Alloteropsis semialata (Poaceae), on Cape York Peninsula, Australia. Australian Journal of Botany 49 , 735-743.

Crowley, G. M., Garnett, S. T. & Shephard, S. (2004). Management guidelines for golden- shouldered parrot conservation . Queensland Parks and Wildlife Service, Brisbane.

Dennis, A. J. (2001). Recovery plan for the northern bettong, Bettongia tropica 2000–2004. Report to Environment Australia, Canberra. Queensland Parks and Wildlife Service, Brisbane.

Dennis, A. J. (2012). Northern bettong Bettongia tropica . In ‘Queensland’s threatened animals’. (Eds L. K. Curtis, A. J. Dennis, K. R. McDonald, P. M. Kyne & S. J. S. Debus.) pp. 366- 367. CSIRO, Canberra.

Harrington, G. N. & Sanderson, K. D. (1994). Recent contraction of wet sclerophyll forest in the wet tropics of Queensland due to invasion by rainforest. Pacific Conservation Biology 1, 319-327.

Johnson, C. N. & McIlwee, A. P. (1997). Ecology of the northern bettong, Bettongia tropica , a tropical mycophagist. Wildlife Research 24 , 549-559.

Jones, K. E., Bielby, J., Cardillo, M., Fritz, S. A., O'Dell, J., Orme, C. D. L., Safi, K., Sechrest, W., Boakes, E. H., Carbone, C., Connolly, C., Cutts, M. J., Foster, J. K., Grenyer, R., Habib, M., Plaster, C. A., Price, S. A., Rigby, E. A., Rist, J., Teacher, A., Bininda- Emonds, O. R. P., Gittleman, J. L., Mace, G. M. & Purvis, A. (2009). PanTHERIA: a species-level database of life history, ecology and geography of extant and recently extinct mammals. Ecology 90 , 2648.

Laurance, W. F. (1996). A distributional survey and habitat model for the endangered northern bettong ( Bettongia tropica ) in tropical Queensland . Report to the Department of Environment, March 1996.

Laurance, W.F. and Harrington, G.N. (1997). Ecological associations of feeding sites of feral pigs in the Queensland Wet Tropics. Australian Wildlife Research 24 , 579-590

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McIlwee, A.P. (1994). The dietary ecology of three mycophagous marsupials in north-eastern Queensland. Honours Thesis. Department of Zoology and Tropical Ecology, James Cook University of North Queensland, Townsville.

Mulder, E., Kanowski, J. & Jensen, R. (2012) . Mount Zero - Taravale fauna and flora survey May 2012 . Australian Wildlife Conservancy, Subiaco.

Pope, L. C., Estoup, A. & Moritz, C. (2000). Phylogeography and population structure of an ecotonal marsupial, Bettongia tropica , determined using mtDNA and microsatellites. Molecular Ecology 9, 2041-2054.

Vernes, K. (2000). Immediate effects of fire on survivorship of the northern bettong ( Bettongia tropica ): an endangered Australian marsupial. Biological Conservation 96 , 305-309.

Vernes, K. (2003). Fine-scale habitat preferences and habitat partitioning by three mycophagous mammals in tropical wet sclerophyll forest, north-eastern Australia. Austral Ecology 28 , 471-479.

Winter, J. W., Johnson, P. M. & Vernes, K. (2008). Northern Bettong Bettongia tropica . In ‘The mammals of Australia.’ Third Edition. (Eds S. Van Dyck & R. Strahan), pp. 293-294. Reed New Holland, Sydney.

Woinarski, J., Burbidge, A. & Harrison, P. (2014). The Action Plan for Australian Mammals 2012. CSIRO Publishing.

Other sources cited in the advice

Department of Environment and Heritage Protection (DEHP) (2013). Northern bettong. Queensland Government. Viewed 22 February 2016. Available on the internet at: https://www.ehp.qld.gov.au/wildlife/threatened-species/endangered/endangered- animals/northern_bettong.html .

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