|Scientific Name:||Pseudomys oralis Thomas, 1921|
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.
|Red List Category & Criteria:||Vulnerable C2a(i) ver 3.1|
|Assessor(s):||Woinarski, J. & Burbidge, A.A.|
|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:|
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).
Native:Australia (New South Wales, Queensland)
|Range Map:||Click here to open the map viewer and explore range.|
|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|
|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:||Pseudomys oralis is not utilized.|
Threats to this species include:
A Recovery Team was established in 1992. The most recent Recovery Plan (DECC 2005) included the major actions:
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 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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