|Scientific Name:||Bettongia lesueur (Quoy & Gaimard, 1824)|
Bettongia lesueuri (Quoy & Gaimard, 1824) [orth. error]
|Taxonomic Notes:||Current taxonomic research based on mitochondrial DNA and morphological data indicates that two separate species might be contained within Bettongia lesueur (Richards 2005). Fossil and subfossil remains also point to the presence of two sympatric taxa similar to the two extant populations on Barrow and Boodie and the ones on Bernier and Dorre.|
|Red List Category & Criteria:||Near Threatened ver 3.1|
|Assessor(s):||Richards, J., Morris, K. & Burbidge, A.|
|Reviewer(s):||Lamoreux, J. & Hilton-Taylor, C. (Global Mammal Assessment Team)|
Listed as Near Threatened because its extent of occurrence is small and it is known from just 6-8 locations, making it close to qualifying for Vulnerable under criterion B1. The natural populations of this species are considered stable and reintroduced populations are increasing, habitat for the species is considered stable, and although there are major threats potentially from introduced predators, fire, and disease, this species has genuinely improved in status since the prior assessment. The species occurs naturally on 3 islands, and has been introduced to another 5 localities. There is, however, uncertainty as to whether 2 of these reintroduction sites can be counted as "self-sustaining", and thus be included in the number of locations used in the assessment. This species is also close to qualifying as having "extreme fluctuations" in population, which would also qualify it for a threatened category.
|Previously published Red List assessments:|
|Range Description:||This species is endemic to Australia, where it was formerly widespread in central, southern, and south-western parts of the country. While it is now presumed to be extinct on the Australian mainland, it persists in insular populations on Bernier and Dorre Islands in Shark Bay (Western Australia) and on Barrow Island off the Pilbara coast (Western Australia) (Richards 2005; Burbidge and Short 2008). |
There are reintroduced populations on Faure Island in Shark Bay and Boodie Island (both Western Australia), as well as on the mainland in Scotia Wildlife Sanctuary (New South Wales), Arid Recovery Reserve at Roxby Downs (South Australia), and Heirisson Prong (Western Australia) (all three mainland sites are fenced reserves within the historical range of the species).
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||It is abundant on Barrow (total 3,400 individuals), Bernier (total of 650 individuals), and Dorre (1,000 individuals). These populations appear to be stable (Richards 2005). The populations on Bernier and Dorre Islands (and presumably Barrow Island and possibly mainland populations) are known to undergo extreme fluctuations in response to rainfall and drought (Short et al. 1997).|
Estimates for the reintroduced island populations are as follows: Boodie (few hundred), Faure Island (150 individuals); it is extinct on Dirk Hartog Island (Burbidge and Short 2008). Reintroduced mainland populations include: Arid Recovery (500), Scotia (300); Heirisson Prong (20). Populations are increasing where reintroduced.
|Current Population Trend:||Increasing|
|Habitat and Ecology:||This species is found in arid and semi-arid areas of shrubland and woodland, on sandy or loose soils. Currently it is found in areas with calcrete rock and sandy areas. It is nocturnal and omnivorous, and lives as loose colonies in a complex warren of underground burrows. The females breed throughout the year and usually give birth to a single young three times a year (J. Richards pers. comm.).|
The current major threats to the natural populations of the species include: the accidental introduction of predators (introduced cats and foxes), fire, and disease (Richards 2005). Introduced rats and mice are also a concern, but to a lesser degree than introduced predators. These same threats apply to varying degrees to the reintroduced populations. Extreme fluctuations in populations on islands are a threat, but this threat is seen as minor relative to the risk exotic predators being introduced (Short et al. 1997). It is also unclear to what extent population fluctuations occur at the reintroduction sites on the mainland. This species would likely qualify as having "extreme fluctuations" in population in terms of the IUCN criteria (IUCN 2001) if it were still restricted to the islands off of Western Australia. This is because these fluctuations are tied to climatic extremes that are likely to be synchronous in these locations, but unlikely to be in synchrony with fluctuations (should they occur) in reintroduced populations in South Australia and New South Wales.
Presumably, overgrazing of suitable habitat by cattle and rabbits, loss of wooded areas to agriculture, as well as changes to the fire regime contributed to the decline of the species on mainland Australia. Introduced species, particularly feral cats and foxes, are thought also to have led to its mainland demise (Richards 2005). Feral cats are a proven threat to this species, as they predated on all animals in a trial reintroduction in the Gibson Desert, Western Australia (A. Burbidge pers. comm.). It is believed to have been extirpated from Dirk Hartog Island by foxes and/or feral cats (Burbidge and Short 2008). The role of disease unclear, but may have been a historical threat.
Black rats were a historical threat to the species on Boodie Island. It suffered greater losses, however, due to a rat-baiting program that accidentally eradicated the species from island in 1985. In 1993 the species was reintroduced to Boodie Island from Barrow Island (Morris 2002).
This species is listed as a threatened species under Australian law. Bernier, Dorre, and Barrow Islands are all protected areas, as are all the areas where the species has been reintroduced. Studies are underway into the taxonomic identity of remaining populations. There is a need to actively manage and monitor populations. This species is listed on Appendix I of CITES.
A recovery plan for the species has been developed for the 2005-2010 period (Richards 2005). Recommendations in this plan include: protect wild populations and their habitat so that the species does not fall below the level of natural fluctuations; maintain captive populations (currently there are captive breeding populations at Yookamurra Wildlife Sanctuary, Scotia Wildlife Sanctuary, and Return to Dryandra Field Breeding Facility); use of population viability analysis to compare the viability of wild, current and potential reintroduced populations, and; enhance community participation and education.
The recovery plan also recommends initiating three reintroductions to the mainland within a five year period (2005-2010) (Richards 2005). There have been reintroduction attempts in the past. Many of these failed do to the presence of introduced predators, and it is clear that success of reintroductions requires sites to be free from cats and foxes. There is a proposed reintroduction to Dirk Hartog Island, which is not possible unless feral cats there have been eradicated (A. Burbidge pers. comm.).
|Citation:||Richards, J., Morris, K. & Burbidge, A. 2008. Bettongia lesueur. The IUCN Red List of Threatened Species 2008: e.T2784A9480530.Downloaded on 18 December 2017.|