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

The Minister approved this conservation advice on 18/06/2015 and included this species in the vulnerable category, effective from 26/06/2015

Conservation Advice Mesembriomys gouldii rattoides

Black-footed tree-rat (north Queensland)

Note: The information contained in this conservation advice was primarily sourced from ‘The Action Plan for Australian Mammals 2012’ (Woinarski et al., 2014). Any substantive additions obtained during the consultation on the draft are cited within the advice. Readers may note that conservation advices resulting from the Action Plan for Australian Mammals show minor differences in formatting relative to other conservation advices. These are reflective of the desire to achieve efficiency over preparation of a large number of advices by adopting the approach of the Action Plan for Australian Mammals in presentation of information and do not reflect any difference in the evidence used to develop the recommendation.

Taxonomy Conventionally accepted as Mesembriomys gouldii rattoides Thomas, 1924.

Three subspecies are recognised:

M. g. melvillensis is proposed for listing in this assessment process as Vulnerable; M. g. gouldii is proposed for listing in this assessment process as Endangered;

Summary of assessment

Conservation status Vulnerable: Criterion 2 B2, (a),(b),(ii),(iii),(v)

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

Reason for conservation assessment by the Threatened Species Scientific Committee This advice follows assessment of information provided in Woinarski, J, C., Z., Burbidge, A. A. and Harrison, P. L. (2014). The Action Plan for Australian Mammals 2012. Collingwood, Australia: CSIRO Publishing to list the black-footed tree-rat (north Queensland).

Public Consultation Notice of the proposed amendment and a consultation document was made available for public comment for 33 business days between 17 December 2014 and 30 January 2015. Any comments received that were relevant to the survival of the species were considered by the Committee as part of the assessment process.

Species/Sub-species Information

Description The black-footed tree-rat (north Queensland) is a nocturnal medium-sized native mammal and one of the largest rodents in Australia (Friend, 1987; Northern Territory Department of Land and Resource Management, 2012). It is a solid rodent with long shaggy medium grey to black fur on top, pale underside, large black ears and a distinctive long hairy tail with terminal white brush (Northern Territory Department of Land and Resource Management, 2012).

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Distribution The distribution of the black-footed tree rat (north Queensland) is poorly known. It has been recorded mostly from eucalypt forests and woodlands (but not rainforests) around Mareeba (Burnett, 2001), but there are records sparsely across Cape York Peninsula (Watts & Aslin, 1981; Dixon & Huxley, 1985), including recent records from Mungkan Kandju National Park and the Australian Wildlife Conservancy’s Piccaninny Plains and Brooklyn wildlife sanctuaries (J. Kanowski, Australian Wildlife Conservancy, pers. comm.).

Relevant Biology/Ecology There is little information available about the ecology of the black-footed tree rat (north Queensland). In north Queensland, this species mostly occurs in eucalypt forests and woodlands, especially where hollows are relatively plentiful. S. Legge (pers. obs.) notes a record of denning in a hollow in a large rainforest tree near rainforest-eucalypt forest boundary at Iron Range. Information on the ecology of the full species is derived from studies of other subspecies. The black-footed tree rat is a nocturnal rodent that dens mostly in tree hollows, but occasionally in dense foliage (notably of Pandanus), and occasionally in buildings. Most knowledge of its ecology derives from studies of the Kimberley and mainland Northern Territory subspecies (notably Friend & Taylor, 1985; Friend, 1987; Rankmore, 2006). It forages on the ground and in trees, and individuals may make movements of at least 500 m from roost sites to foraging areas (Friend et al., 1992).The diet comprises mostly fruits (including of the tough Pandanus spiralis) and seeds, but also includes some invertebrates, flowers and grass (Morton, 1992; Rankmore, 2006; Rankmore & Friend, 2008). Breeding may occur throughout the year, but in the most intensively-studied population (in the Northern Territory) peaked in August-September (Friend, 1987; Rankmore, 2006). Litter size is small (one to three young), and gestation period is 43–44 days, the longest recorded for an Australian rodent (Crichton, 1969). The generation length is taken here to be two years, recognising young reach reproductive maturity at about three months (Crichton, 1969), and longevity is probably three to five years.

Threats Threat factor Consequen Extent over Evidence base ce rating which threat may operate Inappropriate fire severe large likely causal factor in decline regimes (i.e. frequent (Winter & Atherton, 1985) fire) Habitat loss and severe moderate the preferred habitat (tall fragmentation eucalypt open forest) is subject to localised development mostly for horticulture Predation by feral cats severe entire not demonstrated, but plausible Habitat change due to moderate minor not demonstrated, but exotic invasive grasses plausible; invasive grasses will change the ability of this species to forage effectively on the ground, and result in fires that are far more intense Habitat degradation moderate moderate not demonstrated, but and resource depletion possible; particularly through due to livestock and change in understorey plant feral herbivores species composition and vegetation structure, particularly because areas Mesembriomys gouldii rattoides (black-footed tree-rat (north Queensland)) Conservation Advice Page 2 of 9

Threat factor Consequen Extent over Evidence base ce rating which threat may operate supporting feral herbivores can exacerbate incursions of grasses, which then allows fire to carry into the patch, changing the structure. Predation by minor minor not demonstrated, but dogs/dingoes plausible Poisoning and trapping minor minor some deliberate or incidental trapping in relation to it being perceived as a pest to horticultural production; not demonstrated, but possible indirect threat from cane toads if cane toads reduced cat-eating pythons and food- competing goannas and mulgas.

How judged by the Committee in relation to the EPBC Act Criteria and Regulations

Criterion 1. Population size reduction (reduction in total numbers) Population reduction (measured over the longer of 10 years or 3 generations) based on any of A1 to A4 Critically Endangered Endangered Vulnerable Very severe reduction Severe reduction Substantial reduction A1 ≥ 90% ≥ 70% ≥ 50% A2, A3, A4 ≥ 80% ≥ 50% ≥ 30% A1 Population reduction observed, estimated, inferred or suspected in the past and the causes of the reduction (a) direct observation [except A3] are clearly reversible AND understood AND ceased. A2 Population reduction observed, estimated, inferred (b) an index of abundance appropriate to or suspected in the past where the causes of the the taxon reduction may not have ceased OR may not be based on understood OR may not be reversible. (c) a decline in area of occupancy, any of the extent of occurrence and/or quality of A3 Population reduction, projected or suspected to be following: habitat met in the future (up to a maximum of 100 years) [(a) cannot be used for A3] (d) actual or potential levels of A4 An observed, estimated, inferred, projected or exploitation suspected population reduction where the time period must include both the past and the future (up to a (e) the effects of introduced taxa, max. of 100 years in future), and where the causes of hybridization, pathogens, pollutants, reduction may not have ceased OR may not be competitors or parasites understood OR may not be reversible.

Evidence: Insufficient data to determine eligibility Woinarski et al. (2014) notes that the population size of this subspecies is declining, but the rate of decline is unlikely to exceed 30% in any 10-year period. The Committee considers that there is insufficient information to determine the eligibility of the species for listing in any category under this criterion.

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Criterion 2. Geographic distribution is precarious for either extent of occurrence AND/OR area of occupancy Critically Endangered Endangered Vulnerable Very restricted Restricted Limited B1. Extent of occurrence (EOO) < 100 km2 < 5,000 km2 < 20,000 km2 B2. Area of occupancy (AOO) < 10 km2 < 500 km2 < 2,000 km2 AND at least 2 of the following 3 conditions: (a) Severely fragmented OR Number of = 1 ≤ 5 ≤ 10 locations (b) Continuing decline observed, estimated, inferred or projected in any of: (i) extent of occurrence; (ii) area of occupancy; (iii) area, extent and/or quality of habitat; (iv) number of locations or subpopulations; (v) number of mature individuals (c) Extreme fluctuations in any of: (i) extent of occurrence; (ii) area of occupancy; (iii) number of locations or subpopulations; (iv) number of mature individuals

Evidence: Eligible under Criterion 2 B2 (a) (b)(ii)(iii)(v) for listing as Vulnerable Woinarski at al. (2014) notes that categorisation is difficult because there is little known about the distribution, abundance or population trends for this subspecies. It has been recorded at relatively few locations in its north Queensland range: its area of occupancy is inferred to be <2000 km2 (it is estimated at 60 km2, but this is considered a significant under-estimate due to limited sampling across the occupied range); it is currently known from <10 locations; and a decline is inferred from anecdotal information and sampling, decline in habitat quality, habitat loss and fragmentation and predation by feral cats. The Committee considers that the species’ area of occupancy is limited and the geographic distribution is precarious for the survival of the species because its occurrence is limited and decline in area of occupancy, habitat and number of individuals may be inferred.

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Criterion 3. Small population size and decline

Critically Endangered Vulnerable Endangered Low Limited Very low Estimated number of mature individuals < 250 < 2,500 < 10,000 AND either (C1) or (C2) is true C1 An observed, estimated or projected Very high rate High rate Substantial rate continuing decline of at least (up to a 25% in 3 years or 1 20% in 5 years or 3 10% in 10 years or 3 max. of 100 years in future) generation generations generations (whichever is longer) (whichever is (whichever is longer) longer) C2 An observed, estimated, projected or inferred continuing decline AND its geographic distribution is precarious for its survival based on at least 1 of the following 3 conditions: (i) Number of mature individuals in ≤ 50 ≤ 250 ≤ 1,000 each subpopulation (a) (ii) % of mature individuals in one 90 – 100% 95 – 100% 100% subpopulation = (b) Extreme fluctuations in the number of mature individuals

Evidence: Insufficient data to determine eligibility The population size of the black-footed tree-rat (north Queensland) is poorly known. From studies of another subspecies in the Northern Territory, home range size is large (60-70 ha: Rankmore, 2006; Rankmore & Friend, 2008), and the species is mostly solitary, so the total number of individuals in any location is probably small, and it is possible that the population size of this subspecies may be fewer than 10 000 mature individuals. However, this estimate of population size is not based on long-term capture-mark-recapture studies which would provide a more accurate estimate (R. Firth, pers comm.). There are no published estimates of the number of individuals for the black-footed tree rat (north Queensland). Dickman et al. (2000) considered its population size was unknown. In a study sampling mostly wet sclerophyll forests at five sites in the Lamb Range (focusing particularly on the northern bettong Bettongia tropica), Vernes & Pope (2006) captured two individuals from 4916 trap-nights (0.04% trap-success). Studies on another subspecies in the Northern Territory have shown that the black-footed tree rat has a large home range (60-70 ha: Rankmore, 2006; Rankmore & Friend, 2008), so population density (and hence total population) is likely to be relatively low, and the subspecies is unlikely to maintain viable populations in smaller, now isolated, bushland fragments or islands. At some Queensland localities, horticultural plantations (such as of macadamia nuts) may have provided some attraction and benefit to this subspecies, resulting in localised increases in population density (Breed & Ford, 2007); however most clearing of native woodlands and open forests for horticulture is likely to be detrimental to the black-footed tree rat (north Queensland). Dickman, et al. (2000) considered its population size was stable. Winter & Atherton (1985) considered that its abundance had declined on Cape York Peninsula, due mostly to the current regime of frequent fire. A recent attempt to undertake an ecological study of the black-footed tree rat (north Queensland) in the Mareeba area had to be abandoned when no individuals were recorded in intensive sampling, including at sites at which the taxon was previously reported, nor from requests for information from the community (C. Dickman, pers. comm.). Woinarski et al. (2014) notes that the continuing decline in population size may exceed 10% in 10 years.

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The Committee considers that there is insufficient information to determine the eligibility of the species for listing in any category under this criterion. The rate of continuing decline is substantial, but there are insufficient data available on the total number of mature individuals to determine whether the population size is limited. Therefore, the subspecies has not been demonstrated to have met this required element of this criterion.

Criterion 4. Very small population

Critically Endangered Endangered Vulnerable Extremely low Very Low Low

Number of mature individuals < 50 < 250 < 1,000

Evidence: Not eligible Woinarski et al. (2014) notes that the population size is poorly known. From studies of another subspecies in the Northern Territory, home range size is large (60-70 ha: Rankmore 2006; Rankmore and Friend 2008), and the species is mostly solitary, so the total number of individuals in any location is probably small, and it is possible that the population size of this subspecies may be fewer than 10 000 mature individuals. The Committee considers that the total number of mature individuals is approximately 10 000 which is not extremely low, very low or low.

Criterion 5. Quantitative Analysis

Critically Endangered Endangered Vulnerable Immediate future Near future Medium-term future ≥ 50% in 10 years or 3 ≥ 20% in 20 years or Indicating the probability of extinction in generations, 5 generations, ≥ 10% in 100 years the wild to be: whichever is longer whichever is longer (100 years max.) (100 years max.)

Evidence: Insufficient data to determine eligibility Population viability analysis has not been undertaken.

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Conservation Actions

Recovery Plan A recovery plan is not required. Approved conservation advice provides sufficient direction to implement priority actions and mitigate against key threats.

Primary Conservation Objectives Stabilise or increase subpopulations across range, through amelioration of existing threats.

Conservation and Management Actions Theme Specific actions Priority Active mitigation of threats develop or maintain regimes that medium-high reduce frequency and intensity of fire implement cost-effective control medium measures to reduce the abundance or impacts of feral cats maintain patch integrity and increase medium connectivity, especially in regions subject to clearing and intensification of land use Captive breeding n/a Quarantining isolated n/a populations Translocation n/a Monitoring implement integrated monitoring medium program linked to assessment of management effectiveness Community engagement involve Indigenous ranger groups in medium survey, monitoring and management liaise with horticulturalists to minimise low-medium impacts of this subspecies on production, through non-destructive management

Information and research priorities Theme Specific actions Priority Survey to better define survey to resolve distribution (and to medium-high distribution establish which areas may support significant populations) Assess relative impacts of assess the extent to which predation high threats by feral cats is responsible for decline quantify the relative impacts upon high population of a range of current fire regimes, and the mechanisms by which those fire regimes have impacts on this species assess the landscape-scale medium distribution and habitat use of the species, especially in fragmented and modified landscapes Establish or enhance design a monitoring program across medium-high monitoring program range Assess effectiveness of assess the extent to which feasible high [dependent threat mitigation options management options for feral cats upon results can lead to population recovery from above] Mesembriomys gouldii rattoides (black-footed tree-rat (north Queensland)) Conservation Advice Page 7 of 9

Theme Specific actions Priority assess landscape-scale options for high retention of longer-unburnt (>5 years) patches Resolve taxonomic assess genetic relatedness of low-medium uncertainties spatially disparate populations, and the validity of current subspecies demarcation Assess habitat requirements assess factors influencing habitat medium suitability, and characterise habitat preference Assess diet, life history n/a Undertake research to develop broad-scale, targeted feral low-medium develop new or enhance cat control technology existing management mechanisms other establish impacts of the species on medium horticultural production, and mechanisms to reduce any impact

Recommendations (i) The Committee recommends that the list referred to in section 178 of the EPBC Act be amended by including in the list in the Vulnerable category: Mesembriomys gouldii rattoides

AND

(ii) The Committee recommends that there should not be a recovery plan for this subspecies.

Threatened Species Scientific Committee

03/03/2015

References cited in the advice

Breed, B., & Ford, F. (2007). Native mice and rats. Melbourne: CSIRO Publishing. Burnett, S. (2001). The mammals of Mount Molloy Stock Route. Reserves and Spear Creek. Townsville: Environmental Earthworks Services. Crichton, E. G. (1969). Reproduction in the pseudomyine rodent Mesembriomys gouldii (Gray) (Muridae). Australian Journal of Zoology 17, 785-797. Dickman, C. R., Leung, L. K.-P., & Van Dyck, S. M. (2000). Status, ecological attributes and conservation of native rodents in Queensland. Wildlife Research 27, 333-346. Dixon, J. M., & Huxley, L. (1985). Donald Thomson’s mammals and fishes of northern Australia. Melbourne: Nelson. Friend, G. R. (1987). Population ecology of Mesembriomys gouldii (Rodentia: Muridae) in the wet-dry tropics of the Northern Territory. Australian Wildlife Research 14, 293-303. Friend, G. R., & Taylor, J. A. (1985). Habitat preferences of small mammals in tropical open- forest of the Northern Territory. Australian Journal of Ecology 10, 173-185. Friend, G. R., Kemper, C. M., & Kerle, J. A. (1992). Rats of the tree tops. Landscope 8, 10-15. Morton, C. V. (1992). Diets of three species of tree-rat, Mesembriomys gouldii (Gray), M. macrurus (Peters) and Conilurus penicillatus (Gould) from the Mitchell Plateau, Western Australia. B.Sc. (Hons.) thesis, University of Canberra, Canberra.

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Northern Territory Department of Land and Resource Management (2012). Black-footed tree-rat Mesembriomys gouldii. Threatened Species of the Northern Territory. Available on the internet at: http://www.lrm.nt.gov.au/plants-and-animals/threatened-species/specieslist. Rankmore, B. (2006). Impacts of habitat fragmentation on the vertebrate fauna of the tropical savannas of northern Australia; with special reference to medium-sized mammals. Ph.D. thesis, Charles Darwin University, Darwin. Rankmore, B. R., & Friend, G. R. (2008). Black-footed tree-rat Mesembriomys gouldii. In S. Van Dyck & R. Strahan, The mammals of Australia (pp.591-593). Sydney: Reed New Holland. Vernes, K., & Pope, L. C. (2006). Population density of the Northern Bettong Bettongia tropica in northeastern Queensland. Australian Mammalogy 28, 87-92. Watts, C. H. S., & Aslin, H. J. (1981). The rodents of Australia. Sydney: Angus & Robertson. Winter, J. W., & Atherton, R. G. (1985). Survey of the mammals and other vertebrates of the Weipa region, Cape York Peninsula. Queensland Parks and Wildlife Service. Woinarski, J. C. Z., Burbidge, A. A., & Harrison, P. L. (2014). The action plan for Australian mammals 2012. Collingwood, Australia: CSIRO Publishing.

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