Pseudomys oralis 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Mammalia Rodentia Muridae

Scientific Name: Pseudomys oralis Thomas, 1921
Common Name(s):
English Hastings River Mouse, Koontoo
Taxonomic Notes:

No subspecies are recognised. Genetic analyses using mitochondrial DNA have shown that there are seven subpopulations and that each of the subpopulations is genetically isolated and distinct (Jerry et al. 1998, cited in DECC 2005). However, these subpopulations are not distinct subspecies.

Assessment Information [top]

Red List Category & Criteria: Vulnerable C2a(i) ver 3.1
Year Published: 2016
Date Assessed: 2016-02-24
Assessor(s): Woinarski, J. & Burbidge, A.A.
Reviewer(s): Amori, G.
Contributor(s): Smith, A., Murphy, D., Gynther, I., Dickman, C., Meek, P. & Quin, D.

The Hastings River Mouse has a small declining population (<10,000), with all subpopulations holding fewer than 1,000 mature individuals. It is therefore assessed as Vulnerable under criterion C.

Previously published Red List assessments:

Geographic Range [top]

Range Description:

The Hastings River Mouse is patchily distributed in north-eastern New South Wales and far south-eastern Queensland, Australia. It occurs along the Great Dividing Range from near Muswellbrook, New South Wales, north to between Warwick and Tweed Heads in Queensland. Remains in owl deposits in caves show a wider distribution during the late-Pleistocene and early-Holocene (ca 13,000 to 150 years before present) from eastern Victoria to southeastern Queensland (DECC 2005, Bliny et al. 2010), with its range having contracted by ca 65% since European settlement and ca 75% since the Pleistocene (Smith et al. 1996a). Most potential Hastings River Mouse habitat falls within State forests (56%), private land (21%) and national park (18%) (Smith et al. 1996a). DECC (2005) provided a breakdown of the number of capture sites and associated land tenure in New South Wales and Queensland. The majority of capture sites fell in Forestry Estate (49%) comprising Forests NSW Estate (48%) and State Forests of Queensland land (0.9%), and DECC Estate (New South Wales) and Queensland Parks and Wildlife Service managed land (32%), with a smaller number occurring on Freehold Land (9%), Forest Reserve (3%), Local Government (3%), Crown Land (2%), Mining Lease (2%) and Road Reserve. Area of occupancy (AOO) was calculated as 468 km², though this is likely to be an underestimate of the AOO as it is limited by the sampling effort (J. Woinarski pers. comm).

Countries occurrence:
Australia (New South Wales, Queensland)
Additional data:
Continuing decline in area of occupancy (AOO):Yes
Extreme fluctuations in area of occupancy (AOO):NoEstimated extent of occurrence (EOO) - km2:23200
Continuing decline in extent of occurrence (EOO):YesExtreme fluctuations in extent of occurrence (EOO):No
Number of Locations:50Continuing decline in number of locations:Yes
Extreme fluctuations in the number of locations:NoLower elevation limit (metres):300
Upper elevation limit (metres):1250
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:While the Hastings River Mouse can be locally common, its distribution is fragmented (Townley 2000, DECC 2005); the number of mature individuals is small and is estimated to be well below 10,000. Pyke and Read (2002) calculated that about 400 Hastings River Mice had been captured at 50 locations, despite, in some cases, very large trapping efforts in suitable habitat. In most locations where Hastings River Mice have been located, only a single animal was detected. There are limited data on population trends; however, decline can be inferred from continuing—even intensifying—threats in its range. These include inappropriate fires set by pastoralists, overgrazing and logging, and in some areas, removal of logs and other dead timber for firewood. Feral predators would have additional impacts that interact with these habitat-depleting processes. In addition, Pyke and Read (2002) noted five subpopulations that had disappeared since their discovery.
Current Population Trend:Decreasing
Additional data:
Number of mature individuals:5000Continuing decline of mature individuals:Yes
Extreme fluctuations:NoPopulation severely fragmented:Yes
Continuing decline in subpopulations:Yes
All individuals in one subpopulation:No

Habitat and Ecology [top]

Habitat and Ecology:

The Hastings River Mouse occurs in small, often rocky areas in open wet or dry sclerophyll forests and woodlands with native grass, sedge, rush, fern or heath understorey (Smith and Quin 1997, DECC 2005). The presence of a variety of food plants, in particular, native grasses and legumes, is an important factor in determining the presence of the Hastings River Mouse in an area (King 1984, Smith and Quin 1997, Townley 2000, DECC 2005). Diet varies between seasons and locations: leaf material forms the bulk of the winter diet while seeds become more prevalent in summer. Other dietary items include insects, fruit, ferns, moss, flowers and fungi (Fox et al. 1994; Smith et al. 1996b; Townley 2000, 2008; DECC 2005).

Cover appears to be another significant factor in determining suitable habitat. Important structural qualities include dense ground cover of grass, sedge, rush or heath in the height range of 10–75 cm and the presence of shelter sites, including tree root hollows, tree trunk basal cavities, ground holes, rock piles, boulders and fallen logs (Smith and Quin 1997, Townley 2000, Meek 2002).

The impacts of fire on Hastings River Mouse habitat and subpopulations are currently unclear and further information is required to determine the optimal fire regime to maintain habitat and populations (DECC 2005). Smith and Quin (1997) considered that the species has a preference (as measured by abundance and breeding success) for moderate to long unburnt (more than 10 years) sites. They related this preference to increasing species richness of known food plants, density of vegetation cover below one m and the presence of fire refuges, such as minor drainage lines, swamps, seepages or grass flats with seasonally good soil moisture. Further, following wildfire, the Hastings River Mouse was not detected at Boundary Creek during three surveys over an eight year period; the species was detected some 16 years after the fire (DECC 2005). In addition, three surveys of a previously known site at Werrikimbe National Park failed to capture the species following fire (DECC 2005). Billilimbra State Forest supported a low density, but stable population of Hastings River Mouse. The site had not been burnt for at least 10 years, but was burnt by wildfire in 1996. Continuing surveys failed to record the Hastings River Mouse until 1998 (Townley 2000). In contrast, Meek (2002) found that at Marengo State Forest, New South Wales, the Hastings River Mouse was able to breed successfully and repeatedly in habitat that is burnt regularly (less than eight year cycles) (DECC 2005). Meek et al. (2003) also found high population levels of the Hastings River Mouse across seven State Forests, which had fire intervals of less than 10 years, and mostly between two and five years.

With an adult body weight of ca 75-80 g, the Hastings River mouse is the second largest modern member of the genus Pseudomys; only the extinct Long-eared Mouse P. auritus had a larger body weight (c. 120 g). Larger Australian rodents (more than 35 g adult body weight) have suffered a much greater degree of extinction and decline than smaller species (Burbidge and McKenzie 1989).

The Hastings River Mouse has a low reproductive rate for a rodent species (Read 1993, Townley 2000, DECC 2005). Usual litter size is two to three and up to three litters can be produced in one year. Sexual maturity is reached in one year and longevity is three years. Generation length is therefore c. two years.

Continuing decline in area, extent and/or quality of habitat:Yes
Generation Length (years):2
Movement patterns:Not a Migrant

Use and Trade [top]

Use and Trade: Pseudomys oralis is not utilized.

Threats [top]

Major Threat(s): Threats to this species include:
  1. Disjunct, genetically distinct populations (moderate): small, isolated subpopulations have an elevated risk of local extinction; numbers of captures of Hastings River Mouse at most sites are small (e.g. 54% of sites recorded only one capture per survey trip)(DECC 2005); preliminary genetic studies have indicated that individual subpopulations have a moderate degree of inbreeding (Jerry et al. 1998, DECC 2005).
  2. Predation by feral cats (moderate): species within ‘critical weight range’ (Burbidge and McKenzie 1989); these species prone to decline, including decline due to predation by feral Domestic Cats (Felis catus); ameliorated to a degree by presence of Dingos, rock piles, and dense habitat; large rodents seem particularly prone to Cat predation; remains of Hastings River Mice have been found in a feral Cat’s stomach (DECC 2005); Smith and Quin (1996) demonstrated a spatial pattern of decline and extinction in Conilurine rodents associated with the presence of Red Foxes (Vulpes vulpes) and Cats (and their prey, such as Rabbits and mice).
  3. Predation by Red Foxes (moderate): species in ‘critical weight range’ (Burbidge and McKenzie 1989); these species prone to decline, including decline due to predation by Red Foxes; ameliorated to a degree by presence of Dingos, rock piles, and dense habitat; remains of Hastings River Mice have been found in Red Fox scats collected from several sites (DECC 2005); Smith and Quin (1996) demonstrated a spatial pattern of decline and extinction in Conilurine rodents associated with the presence of Red Foxes and Cats (and their prey, such as Rabbits and mice); penetration of foxes into Hastings River Mouse habitat is potentially increased by formation of roads and tracks during forestry operations (DECC 2005).
  4. Timber harvesting and forest management (moderate): timber harvesting activity impacts adversely on the Hastings River Mouse by reducing shelter provided by hollow logs and old-growth stems with basal cavities; harvesting activities also open up the understorey and create roads and tracks potentially leading to increased predation pressure; the Hastings River Mouse has been found in logged areas (Meek et al. 2003), however, the largest and most stable subpopulations located to date occur in unlogged old-growth forest (Townley 2000, DECC 2005); also forest management affects this species by too frequent burning and by baiting Dingos which predate Red Foxes and Cats.
  5. Inappropriate fire regimes (moderate): no experimental evidence; the response of a number of subpopulations to fires of varying intensity has not resulted in a clear pattern; one subpopulation could not be detected until 16 years after a wildfire, but subpopulations occur in areas burnt at frequencies of less than every 10 years and in some areas every 2-5 years (Meek et al. 2003, DECC 2005); significant positive correlation with time since fire up to 10 years (Smith and Quin 1997).
  6. Habitat loss and fragmentation (minor): clearing and habitat disturbance increase isolation of subpopulations; species is generally absent from potential habitat where areas with more than 10% clearing occur within a 2 km radius of the potential habitat (Smith et al. 1996a, DECC 2005); range reduced to heavily forested parks and timber production forests where clearing is not currently a threat except in mining leases; mesic encroachment of the grassy understorey of some sites is occurring (DECC 2005).
  7. Habitat degradation and resource depletion due to livestock and feral herbivores (minor): grazing impacts on the Hastings River Mouse by removing or trampling palatable herbs and grasses and altering ground cover (shelter) and floristics; in addition, burning by graziers is frequently used as a management tool to promote feed for grazing stock in many areas in northern New South Wales and south-east Queensland (DECC 2005).

Conservation Actions [top]

Conservation Actions: A Recovery Team was established in 1992. The most recent Recovery Plan (DECC 2005) included the major actions:
  • Research. This involves genetics research, research focusing on the impacts of threatening processes and development of mitigation measures and refining habitat and microhabitat models.
  • Population surveys and mapping to identify new populations, define the boundaries of known subpopulations and identify potential dispersal corridors between known populations within subpopulation boundaries.
  • Monitoring to review and assess conservations status of individual populations and the species as a whole and refine management.
  • Management. This includes population management and developing environmental impact assessment guidelines.
  • Community and Public Authority involvement to increase awareness and involvement in management and engage private landholders in conservation of populations on private land.
The National Recovery Plan has identified seven genetically distinct subpopulations, each of which needs to be managed as a separate management unit to maintain genetic diversity. Recovery objectives and actions outlined in the Plan include the development of population management programs using the best available information and development of Environmental Impact Assessment guidelines. Interim Hastings River Mouse management guidelines cover fire protection, timber harvesting, predator control, vegetation clearing and grazing mitigation prescriptions.

Current management of the Hastings River Mouse includes habitat and population protection measures in state forests (DECC 2005). In New South Wales, an Integrated Forestry Operations Approval is granted under the New South Wales Forestry and National Park Estate Act 1998 and regulates the undertaking of certain forestry activities in the public forests of a region. The terms of a Threatened Species Licence outline minimum protection measures required to restrict the impacts of forestry activities on threatened species and their habitats, and provide the basis for the Department of Environment and Climate Change’s (DECC) regulation and monitoring of compliance of those activities. Prescriptions also outline the manner in which targeted surveys and habitat suitability assessments for the Hastings River Mouse must be undertaken (Appendix 1 of DECC 2005)

At the Border Ranges National Park, six long-term small mammal monitoring sites have been established to provide information on population dynamics of the Hastings River Mouse in response to fire (DECC 2005). Vegetation monitoring is also undertaken at 54 monitoring plots to collect data on habitat change over time (DECC 2005). The Lamington National Park and Gambubal Forest Reserve populations are monitored annually in January and autumn, respectively. An annual monitoring program was initiated at the former location because at the time of its discovery the subpopulation was an isolated one, being the first recorded from the McPherson Range (Gynther and O’Reilly 1995). Monitoring has been conducted at the most accessible site, Duck Creek Road, since 1999. Townley (2000) identified the Gambubal subpopulation of the Hastings River Mouse as being the most abundant of any she surveyed in Queensland and New South Wales, making it significant on a national scale. An annual monitoring program commenced there in 2005 after a wildfire in August 2004 burnt the entire site, removing all ground storey vegetation (I. Gynther pers. comm.).

Errata [top]

Errata reason: This errata assessment has been created because the map was accidentally left out of the version published previously.

Citation: Woinarski, J. & Burbidge, A.A. 2016. Pseudomys oralis (errata version published in 2017). The IUCN Red List of Threatened Species 2016: e.T18554A115143455. . Downloaded on 19 September 2018.
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