Biodiversity

Species Profile and Threats Database


For information to assist proponents in referral, environmental assessments and compliance issues, refer to the Policy Statements and Guidelines (where available), the Conservation Advice (where available) or the Listing Advice (where available).
 
In addition, proponents and land managers should refer to the Recovery Plan (where available) or the Conservation Advice (where available) for recovery, mitigation and conservation information.

EPBC Act Listing Status Listed as Endangered
Recovery Plan Decision Recovery Plan required, this species had a recovery plan in force at the time the legislation provided for the Minister to decide whether or not to have a recovery plan (19/2/2007).
 
Adopted/Made Recovery Plans Revised Recovery plan for the Carpentarian Rock-rat Zyzomys palatalis (Puckey, H., J. Woinarski & C. Trainor, 2003) [Recovery Plan].
 
Other EPBC Act Plans Threat Abatement Plan for Predation, Habitat Degradation, Competition and Disease Transmission by Feral Pigs (Australian Government Department of the Environment and Heritage (AGDEH), 2005p) [Threat Abatement Plan].
 
Policy Statements and Guidelines Survey guidelines for Australia's threatened mammals. EPBC Act survey guidelines 6.5 (Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2011j) [Admin Guideline].
 
Federal Register of
    Legislative Instruments
Declaration under s178, s181, and s183 of the Environment Protection and Biodiversity Conservation Act 1999 - List of threatened species, List of threatened ecological communities and List of threatening processes (Commonwealth of Australia, 2000) [Legislative Instrument].
 
State Government
    Documents and Websites
NT:Threatened Species of the Northern Territory - Carpentarian Rockrat Zyzomys palatalis (Puckey, H. & J. Woinarski, 2006) [Information Sheet].
State Listing Status
NT: Listed as Critically Endangered (Territory Parks and Wildlife Conservation Act 2000 (Northern Territory): 2012 list)
Non-statutory Listing Status
IUCN: Listed as Critically Endangered (Global Status: IUCN Red List of Threatened Species: 2013.1 list)
Scientific name Zyzomys palatalis [25907]
Family Muridae:Rodentia:Mammalia:Chordata:Animalia
Species author Kitchener,1989
Infraspecies author  
Reference  
Distribution map Species Distribution Map

This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.

Illustrations Google Images

The Carpentarian Rock-rat is a small rodent with grey-brown fur. Growing to an average body length of 19.7 cm and weighing up to 136 g, the Carpentarian Rock-rat has a carrot shaped relatively hairy tail in which fat deposits are stored. The tail grows to approximately 15 cm long and has longer hairs at the tip (Puckey et al. 2004, Strahan 1998). As with other Rock-rats, the Carpentarian Rock-rat is known to lose its tail, fur and skin very easily (Puckey et al. 2004) and the species is often captured with a broken off tail forming a stump (Puckey & Woinarksi 2006).

The Carpentarian Rock-rat is known from just five locations, all within a radius of 35 km, in the Northern Territory (adjacent to the Queensland border) (Puckey & Woinarksi 2006, Puckey et al. 2003). The Carpentarian Rock-rat is estimated to have an area of occupancy of less than 10 km2 (Bowman et al. 2006).

It is known from five locations (gorges and escarpments) on Wollogorang Station (Puckey & Woinarksi 2006):

  • Banyan Gorge
  • Camel Creek
  • Moonlight Gorge
  • McDermott Springs
  • Redbank Mine.

There are currently 17 Carpentarian Rock-rats being maintained in a captive breeding colony at the Territory Wildlife Park in the Northern Territory (Puckey et al. 2003).

Whilst initially considered fragmented, studies have shown that the closed rainforest habitat preferred by the species has been increasing in the known range of the species. The Carpentarian Rock-rat will also utilize more than one vegetation type, and has been observed through the foraging of the species in savannah margins (Bowman et al. 2006).

The Carpentarian Rock-rat is known from five populations in the Gulf of Carpentaria hinterland, Northern Territory (Puckey & Woinarksi 2006). It is suggested by Bowman and colleagues (2006) to be likely one metapopulation. The total population is estimated to be fewer than 2000 individuals (Puckey & Woinarksi 2006). Extrapolation of population size from density estimates at two populations indicated a number of 696 at Moonlight Gorge and 450 at Banyon Gorge in 1996 (Trainor et al. 2000). No estimates are available for other sites.

Boulder-fields and thickets

The Carpentarian Rock-rat is a nocturnal rodent, sheltering during the day in cracks between boulders, caves and crevices (Begg and Dunlop 1980; 1985, cited in Puckey et al. 2003). The main habitat requirements of the Carpentarian Rock-rat appear to be large, rugged, sandstone gorges with scree and rock slopes covered with dry monsoon vine thicket and woodland (Lee 1995; Trainor et al. 2000).

Spring water

Populations are often within 100 m of permanent spring water. Vine thicket species including Ficus virens, F. platypoda, Gyrocarpus americanus, Owenia vernicosa, Terminalia carpentariae, Pouteria sericea, Celtis philippinensis and Buchanania obovata with an understorey of vines Caesalpinea bonduc, Opilia amentacea, Pisonia aculeata and Sarcostemma australe. The surrounding vegetation is predominently Eucalyptus papuana/E. miniata woodland with Plectrachne pungens understorey (Lee 1995).

Carpentarian Rock-rats generally have a 1:1 sex ratio in a population and a short life-span (Puckey et al. 2004, Trainor et al. 2000). As with all rock-rats, reproductive output is characteristically low with females giving birth to 1–3 young per litter. Females that live into their second year have been recorded as producing up to four litters. Breeding in the Carpentarian Rock-rat has been reported in most months (Puckey et al. 2004, Trainor et al. 2000).

The species has been recorded eating seeds of Terminalia carpentariae, Pandanus aquaticus, Livistona inermis and Owenia vernicosa (Churchill 1996). Faecal analysis indicates that 84% of the Carpentarian Rock-rat's diet consists of fruits and dicotyledon seeds (seeds containing two embryonic leaves) (Puckey et al. 2004). Its large incisors allow it to chew through the woody nuts of many of these species to access the kernel, and distinctively chewed nuts are a characteristic sign of its presence. This diet is common to all the rock-rats, and information from the more intensively-studied Arnhem Land Rock-rat is probably generally applicable to the Carpentarian Rock-rat (Puckey et al. 2003).

There is no significant difference in the size of the home range or core area of males and females of this species, though juveniles have a significantly smaller home range than adults. The species is noted to prefer the slopes and valley area of gorges, or the ecotone between these two areas, rather than the surrounding plateaus, making many short distance foraging moves interspersed with longer forays that occur irregularly (Puckey et al. 2004). Based on a radio-tracking study of 21 individuals, Puckey and colleagues (2004) calculated a mean home range size of 1.1 ha. Individuals may move up to 2 km in one night, and while most activity occurred within monsoon rainforests, some individuals would also forage within nearby areas of savanna woodland. No animals moved more than 80 m away from the edge of rainforest (Puckey et al. 2004).

Land Tenure

As all locations are on a single pastoral lease and no known populations exist inside reserves, the security of the species is considered poor (Woinarski 2000). The species is likely to disperse along creeklines in known habitat, and may colonize surrounding gorges, therefore the protection of these areas is essential to maintain or recover the species (Bowman et al. 2006).

Whilst population numbers have been reported to have increased in the past 50 years (Bowman et al. 2006), the habitat patches that the Carpentarian Rock-rat occurs in are still limited. As these habitat patches provide rich resources for the Carpentarian rock-rat, it can occur in high densities in the known patches.

Frequent fires

Annual and more frequent fires are considered a threat to the monsoonal rainforest habitat and many individuals (Churchill 1996, Puckey et al. 2004). Population viability analysis by Brook and colleagues (2002) predicted the species' sensitivity to frequent, hot, late dry-season fires, with the progressive habitat degradation likely to substantially reduce the overall population size and lead to the probable extinction of the species within 100 years, though data from Bowman and colleagues (2006) suggests habitat loss has not been so severe.

Exotic species

Other threats to this species include grazing by feral animals and stock and weed intrusion (Puckey et al. 2004), and it is reported the habitat is also under threat from feral pigs (Churchill 1996).

The following objectives are identified in the Carpentarian Rock-rat Recovery Plan (Puckey et al. 2003):

  • Develop and implement appropriate management strategies to maintain known populations.
  • Continue research into ecology and population demography to fill current information gaps.
  • Continue to adapt established PVA models as new information becomes available.
  • Maintain a viable captive breeding population.
  • Investigate aspects of the biology of Carpentarian Rock-rats using captive animals.
  • Experimentally release captive bred individuals into potentially suitable areas not currently occupied.
  • Raise the profile of Carpentarian Rock-rats in the community.

Brook and colleagues (2002) suggested that the most effective management strategy to counteract the threat of wildfire would be regular, controlled, fuel reduction burns in the vegetation around gorge entrances where the species persists during the early dry season. The Parks and Wildlife Commission of the Northern Territory (PWCNT) are establishing fire management programs for each of the known sites under a cooperative management agreement with the land holder. All areas surrounding the four known habitats are currently de-stocked and intended to remain that way for the immediate future (Puckey et al. 2003).

Establishing a new population (through translocation of captive-bred individuals) is also suggested as a means of studying the ecological requirements of the species and the impact of threats, if conducted under adaptive management experiment guidelines (Brook et al. 2002). Two trial translocation programs have been attempted recently, in apparently suitable habitat at Limmen National Park, but neither was a success (Puckey & Woinarksi 2006).

Management documents for the Carpentarian Rock-rat include:

  • Threat Abatement Plan for Predation, Habitat Degradation, Competition and Disease Transmission by Feral Pigs (AGDEH 2005p).

The following table lists known and perceived threats to this species. Threats are based on the International Union for Conservation of Nature and Natural Resources (IUCN) threat classification version 1.1.

Threat Class Threatening Species References
Agriculture and Aquaculture:Livestock Farming and Grazing:Grazing pressures and associated habitat changes Distribution, habitat and status of the Carpentarian rock-rat, Zyzomys palatalis. Wildlife Research. 23:77-91. (Churchill, S.K., 1996) [Journal].
Revised Recovery plan for the Carpentarian Rock-rat Zyzomys palatalis (Puckey, H., J. Woinarski & C. Trainor, 2003) [Recovery Plan].
Multiscale patterns of habitat use by the Carpentarian rock-rat (Zyzomys palatalis) and the common rock-rat (Z. argurus). Wildlife Research. 27:319-332. (Trainor, C., A. Fisher, J. Woinarski & S. Churchill, 2000) [Journal].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or predation Felis catus (Cat, House Cat, Domestic Cat) Distribution, habitat and status of the Carpentarian rock-rat, Zyzomys palatalis. Wildlife Research. 23:77-91. (Churchill, S.K., 1996) [Journal].
Revised Recovery plan for the Carpentarian Rock-rat Zyzomys palatalis (Puckey, H., J. Woinarski & C. Trainor, 2003) [Recovery Plan].
Multiscale patterns of habitat use by the Carpentarian rock-rat (Zyzomys palatalis) and the common rock-rat (Z. argurus). Wildlife Research. 27:319-332. (Trainor, C., A. Fisher, J. Woinarski & S. Churchill, 2000) [Journal].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Grazing, tramping, competition and/or habitat degradation Sus scrofa (Pig) Distribution, habitat and status of the Carpentarian rock-rat, Zyzomys palatalis. Wildlife Research. 23:77-91. (Churchill, S.K., 1996) [Journal].
Multiscale patterns of habitat use by the Carpentarian rock-rat (Zyzomys palatalis) and the common rock-rat (Z. argurus). Wildlife Research. 27:319-332. (Trainor, C., A. Fisher, J. Woinarski & S. Churchill, 2000) [Journal].
Natural System Modifications:Fire and Fire Suppression:Inappropriate and/or changed fire regimes (frequency, timing, intensity) Revised Recovery plan for the Carpentarian Rock-rat Zyzomys palatalis (Puckey, H., J. Woinarski & C. Trainor, 2003) [Recovery Plan].
Natural System Modifications:Fire and Fire Suppression:Inappropriate prescribed regimes and/or vegetation management to control fire regimes Distribution, habitat and status of the Carpentarian rock-rat, Zyzomys palatalis. Wildlife Research. 23:77-91. (Churchill, S.K., 1996) [Journal].
Protected status:Protected status:Lack of secure conservation land tenure Zyzomys palatalis in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006xj) [Internet].

Australian Faunal Directory (2010a). Australian Biological Resources Study - species Zyzomys palatalis. In: Zyzomys palatalis. Page(s) 1989. [Online]. Available from: http://www.environment.gov.au/biodiversity/abrs/online-resources/fauna/afd/taxa/Zyzomys_palatalis.

Australian Government Department of the Environment and Heritage (AGDEH) (2005p). Threat Abatement Plan for Predation, Habitat Degradation, Competition and Disease Transmission by Feral Pigs. [Online]. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/tap/pig.html.

Bowman, D.M.J.S., D.L. McIntyre & B.W. Brook (2006). Is the Carpentarian Rock-rat Zyzomys palatalis critically endangered. Pacific Conservation Biology. 12:134-139.

Brook, B.W., A.D. Griffiths & H.L. Puckey (2002). Modelling strategies for the management of the critically endangered Carpentarian rock-rat (Zyzomys palatalis) of northern Australia. Journal of Environmental Management. 65(4):355-368.

Churchill, S.K. (1996). Distribution, habitat and status of the Carpentarian rock-rat, Zyzomys palatalis. Wildlife Research. 23:77-91.

Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC) (2011j). Survey guidelines for Australia's threatened mammals. EPBC Act survey guidelines 6.5. [Online]. EPBC Act policy statement: Canberra, ACT: DSEWPAC. Available from: http://www.environment.gov.au/epbc/publications/threatened-mammals.html.

International Union for Conservation of Nature (IUCN) (2010). IUCN Red List of Threatened Species. Version 2010.4. [Online]. Available from: http://www.iucnredlist.org.

Lee, A.K. (1995). The Action Plan for Australian Rodents. Canberra: Australian Nature Conservation Agency, Endangered Species Program.

Puckey, H. & J. Woinarski (2006). Threatened Species of the Northern Territory - Carpentarian Rockrat Zyzomys palatalis. [Online]. Available from: http://lrm.nt.gov.au/plants-and-animals/threatened-species/specieslist.

Puckey, H., M. Lewis, D. Hooper & C. Michell (2004). Home range, movement and habitat utilisation of the Carpentarian rock-rat (Zyzomys palatalis) in an isolated habitat patch. Wildlife Research. 31(3):327-337. [Online]. Available from: http://www.publish.csiro.au/nid/144/paper/WR03025.htm.

Strahan, R. ed (1998). The Mammals of Australia, Second Edition, rev. Sydney, NSW: Australian Museum and Reed New Holland.

Trainor, C., A. Fisher, J. Woinarski & S. Churchill (2000). Multiscale patterns of habitat use by the Carpentarian rock-rat (Zyzomys palatalis) and the common rock-rat (Z. argurus). Wildlife Research. 27:319-332.

Woinarski, J.C.Z. (2000). The conservation of rodents in the monsoonal tropics of the Northern Territory. Wildlife Research. 27(4):421-435.

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This database is designed to provide statutory, biological and ecological information on species and ecological communities, migratory species, marine species, and species and species products subject to international trade and commercial use protected under the Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act). It has been compiled from a range of sources including listing advice, recovery plans, published literature and individual experts. While reasonable efforts have been made to ensure the accuracy of the information, no guarantee is given, nor responsibility taken, by the Commonwealth for its accuracy, currency or completeness. The Commonwealth does not accept any responsibility for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the information contained in this database. The information contained in this database does not necessarily represent the views of the Commonwealth. This database is not intended to be a complete source of information on the matters it deals with. Individuals and organisations should consider all the available information, including that available from other sources, in deciding whether there is a need to make a referral or apply for a permit or exemption under the EPBC Act.

Citation: Department of the Environment (2014). Zyzomys palatalis in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Tue, 29 Jul 2014 18:42:14 +1000.