No subspecies are recognised for Leporillus conditor.

Over the period since European colonisation of Australia (1788) to the 1930s, the Greater Stick-nest Rat was extirpated from a vast range on the Australian mainland, but fortunately it survived on two small inter-connected islands. Since the 1990s, a series of translocations to sites protected from introduced predators have increased the conservation security of the species. This likely resulted in increases in population size, area of occupancy (AOO), extent of occurrence (EOO) and number of locations in the previous assessment period (2004–14); however, notwithstanding subsequent translocations, this increase has not been sustained over the current assessment period (2014–24), although if establishment of the recently translocated subpopulations at Dirk Hartog Island (Western Australia) and Mallee Cliffs National Park (New South Wales) are successful, this is likely to lead to a future population and AOO increase.

However, translocations have had mixed success, and trends over the period most relevant to this assessment are not well resolved. This is because there are inter-annual fluctuations at some sites, monitoring data are limited, some translocations that were considered to be established have subsequently failed, subpopulations at some translocation sites appear to be declining, it may be too early to confirm establishment at some locations, and longer-term trends for lower rainfall across southwestern Australia may lead to future declines.

Focusing on the five currently established sites and locations, this species has an AOO of c. 52 km². A continuing decline is not definitively projected, but it is possible that climate change – which is currently causing rainfall decline in the southwest of Western Australia – could drive the loss of subpopulations, and therefore EOO, AOO and the number of mature individuals. Thus, the Greater Stick-nest Rat is assessed at Near Threatened, as it is close to qualifying for EN B2ab(i,ii,iii,iv,v) when five locations are considered, and if the risks posed to this species intensify. However, should the recently-translocated subpopulations become successfully established, its number of locations, EOO and AOO will improve.

Subfossil data combined with information from early explorers and naturalists show that the distribution of Stick-nest Rats (Leporillus conditor and L. apicalis) formed arcs along the southeastern, southern and southwestern boundaries of the arid zone, from western Victoria to North West Cape. The Greater Stick-nest Rat (L. conditor) had a more restricted distribution along the arid zone boundary than did the Lesser Stick-nest Rat (L. apicalis). It did not occur in the Great Victoria Desert, and was probably absent from the northern parts of the Eastern Goldfields of Western Australia. There is little evidence of it much southwest of the arid zone boundary. However, unlike the Lesser Stick-nest Rat, it did occur all over the Nullarbor Plain (A. Baynes pers. comm. 2010).

The Greater Stick-nest Rat became extinct on mainland Australia in the 1930s, remaining today only on East Franklin Island (2.25 km²) and West Franklin Island (2.47 km²), South Australia (Copley 1988, 1999). It has been translocated, for conservation purposes, to multiple sites. Translocations have failed in Yookamurra (11.1 km²), Venus Bay (11.1 km²), Arid Recovery (14 km²) (South Australia), Heirisson Prong (12 km²) and Faure Island (58 km²) (Shark Bay), and Scotia (40 km²) and Sturt National Park (New South Wales), although this latter site is a very recent attempt. Conversely, translocated populations remain established on Reevesby Island (3.4 km²) and Saint Peter Island (40.3 km²) (South Australia), and Salutation Island (1.63 km²) (Western Australia). Newer translocations (from 2011 onwards) have occurred at the following localities, where establishment is currently tenuous or too early to call: Mt Gibson (78 km²) (Western Australia), Mallee Cliffs (40 km²) (New South Wales), and Dirk Hartog Island (633 km²) (Shark Bay, Western Australia). Thus, the map accompanying this assessment shows the currently confirmed, established localities only: the Franklin Islands (remnant), and Reevesby, Saint Peter and Salutation Islands (introduced).

The current area of occupancy (AOO) is c. 50–300 km², with the three aforementioned translocation sites that are currently either tenuous or with translocations that are too early to know if they have been successful. If the two most recent translocations (Dirk Hartog Island and Mallee Cliffs) are excluded as required by the Red List Guidelines (since five years have not passed since the introduction), and Mt Gibson is also excluded as the survival of the subpopulation there is currently tenuous, there are five locations (all islands) and the AOO is c. 52 km².

The current population size is not well resolved. Population and abundance data for most subpopulations was compiled by Short et al. (2019). The likely current population is c. 2,800 to 3,600 individuals. Population trends have been inconstant due to translocations, followed by some failures, and are subject to inter-year variation driven by rainfall.

Based largely on the review by Short et al. (2019), with some updated information (e.g., DBCA 2023) and expert advice, the following is a summary of the status of all subpopulations.

Original (remnant) subpopulations:

(1) East Franklin Island, South Australia (2.25 km²). Population estimated at c. 500 individuals in 1988 (Copley 1988), with subsequent fluctuations in abundance reported by Short et al. (2019). With low confidence, population size in 2014 was 500, and in 2024 was 500.

(2) West Franklin Island, South Australia (2.47 km²). Connected at low tide to East Franklin. Population estimated at c. 500 individuals in 1988 (Copley 1988), with subsequent fluctuations in abundance reported by Short et al. (2019). With low confidence, population size in 2014 was 500, and in 2024 was 500.

A 2011 visit to the Franklin Islands to source animals for release at Mt Gibson Sanctuary (WA) found stick-nest rats to be relatively common and easy to obtain for the translocation (Short et al. 2019). There are no data suggesting a significant decline since then, so the 2024 subpopulation size is c. 1,000.

Translocations:

(3) Reevesby Island, South Australia (3.44 km²). Translocations from 1990. Population estimated at 600–1,000 individuals in 2012 in Woinarski et al. (2014), with low confidence. Short et al. (2019) indicated that abundance may have declined subsequently; so, with low confidence, the population size in 2024 may be c. 500–1,000.

(4) Salutation Island, Western Australia (1.63 km²). Translocations from 1990. Population estimated at <500 individuals in Short et al. (2019), prior to 2018, but they noted indications of decline subsequently; so, noting recent drought, population size in 2024 may be c. 50–100.

(5) Yookamurra, South Australia (11.1 km²). Translocations from 1991. Failed by 2007.

(6) Saint Peter Island, South Australia (40.3 km²). Translocations from 1993. Population estimated at 1,000 individuals in 2012 in Woinarski et al. (2014), with low confidence; so, population size in 2024 may be c. 1,000.

(7) Venus Bay, South Australia (11.1 km²). Translocations from 1995. Failed by 1996.

(8) Arid Recovery, South Australia (14 km²). Translocations from 1998. Population estimated at 350 individuals in 2017 in Short et al. (2019), subsequently failed.

(9) Heirisson Prong, Shark Bay, Western Australia (12 km²). Translocations from 1999. Failed by 2014.

(10) Faure Island, Shark Bay, Western Australia (58 km²). Translocations from 2006. Failed by 2008.

(11) Scotia, New South Wales (40 km²). Translocations from 2006. Failed by 2014.

(12) Mt Gibson, Western Australia (78 km²). Translocations established from Franklin Islands stock in 2011; and this population was released into a large mainland island (predator-free fenced area) in the Sanctuary (7,832 ha) in 2014. These individuals were supplemented with additional releases in 2015 and 2018–19, and established at two main locations on-site. Record low rainfall in 2023, coupled with continued drought conditions and extreme temperatures into 2024, and potentially suboptimal habitat, have impacted persistence at these sites and the subpopulation size now may be <10 individuals. As such the continued viability at Mt Gibson is yet to be determined.

(13) Mallee Cliffs, New South Wales (40 km²). Translocations from 2020. Animals were translocated from a captive breeding program re-established at Monarto Safari Park 2019, founded from Franklin Islands. Greater Stick-nest Rats are persisting onsite, and the population appears to be establishing, but there is no estimate of subpopulation size. Plausibly could be established; population <100.

(14) Dirk Hartog Island, Shark Bay, Western Australia (633 km²). Translocations from 2021. Plausibly now established; but occupying only a small proportion of the island to date, say 10–20 km². No recent estimate of population size. Some recent indication of local establishment and possible expansion in area occupied (DBCA 2023).

(15) Wild Deserts, Sturt National Park, New South Wales. 32 individuals, all captured from Reevesby Island, were translocated in May 2023, but 75% of these died within five days. The survivors were re-captured and moved to a captive breeding population (https://us7.campaign-archive.com/?u=bb499ea0b610866ef34d6c1a2andid=75dc9db5dd).

The Greater Stick-nest Rat is found in areas of perennial succulent and semi-succulent shrubland. Animals shelter in constructed stick nests, seabird burrows and amongst rocks (Lee 1995). Females give birth to between one and three young after a gestation period of 44 days (Robinson 2008). It typically lives in family groups of 5–20 individuals. Diet is strongly selective, favouring succulent vegetation (chenopods and other species with high water content).

The major threat for Greater Stick-nest Rats is predation by feral cats (Felis catus) and Red Foxes (Vulpes vulpes). Both species have caused the extinction of medium-sized mammals on the Australian mainland and on Australian islands (Copley 1999, Burbidge and Manly 2002). All current populations are at sites without cats and/or foxes.

Short et al. (2019) indicated that Black Rats (Rattus rattus) may be a threat, citing an instance of predation by Black Rats on a juvenile Stick-nest Rat. Translocated populations have also been shown to be highly susceptible to predation by native reptiles (snakes, monitors Varanus spp.) and birds.

Island subpopulations of Greater Stick-nest Rat may be susceptible to disease (Adams and Fenwick 2004) and declining rainfall/increased temperatures due to climate change. Furthermore, failure to maintain mainland island and captive colonies may be an issue: there have been some problems with captive colonies, including obesity and cataracts, and a majority of translocations to mainland islands have failed. Reduction in genetic diversity may be a current and future problem, given the small source population (Short et al. 2019), although management seeks to move animals amongst some sites to help prevent inbreeding (White et al. 2020, Onley et al. 2023).

Reintroduced populations may be highly vulnerable to climate change and increased drought and heat stress, as experienced in subpopulations at Arid Recovery and Mt Gibson. Some translocations may have failed due to insufficient area of suitable habitat.

The Greater Stick-nest Rat is not utilised.

Sustained conservation management actions over the last few decades have led to significant improvements in the conservation status of this species. It will continue to be dependent on ongoing management.

When the first draft recovery plan for the Greater Stick-nest Rat was written in 1993, the species was listed nationally as Endangered. That recovery plan (Copley 1993, revised 1994 and 1995), had a stated objective of upgrading the conservation status to Vulnerable within five years. That objective was met through: maintaining the Franklin Island population(s), establishing an effective captive breeding program, increasing the number of wild populations from one to three (or more), substantially increasing the geographic spread of these populations within the species’ known former range, and increasing the number of mature individuals from c. 1,000 to c. 5,000 (or more), with each population consisting of at least 500 mature individuals (the equivalent of each of the two Franklin Islands). Current population size is estimated, with low confidence, to be 2,800.

The ‘Review of the Recovery Plan for the Greater Stick-nest Rat, Leporillus conditor’ (Copley 1999b), noted that all five success criteria had been met and as a result of its recommendation the species status listing was downlisted from Endangered to Vulnerable. This is significant as it is one of few Australian mammal species to have changed status in a positive direction due to management and to have sustained that recovery. Since that time further subpopulations have been established, increasing overall extent of occurrence (EOO), area of occupancy (AOO), number of subpopulations, and population size; however, some translocations have failed (Short et al. 2018, 2019), including some that had persisted for 20+ years (Moseby et al. 2024).

The Franklin Islands subpopulation was the source of animals for a captive-breeding programme, commenced in 1985, which in turn became the source for translocations to islands and mainland islands. Greater Stick-nest Rats were introduced to Reevesby Island, South Australia, in 1990, to Saint Peter Island, South Australia, in 1993-94 (Robinson 2008), to Salutation Island, Western Australia, in 1990 (Morris 2000). Later reintroductions to Mt Gibson Sanctuary, Mallee Cliffs (2020) and Dirk Hartog Island (2021) were a mix of wild-wild translocations from island stock and captive breeding programmes founded with animals from islands.

The Franklin Islands are within the Nuyts Archipelago Wilderness Protected Area, and Saint Peter Island is part of the Nuyts Archipelago Conservation Park, both managed by the South Australian Department of Environment, Water and Natural Resources. Reevesby Island is part of the Sir Joseph Banks Group Conservation Park, also managed by the South Australian Department of Environment, Water and Natural Resources. Salutation Island is a nature reserve and Dirk Hartog Island is a national park, both managed by the Western Australian Department of Biodiversity, Conservation and Attractions.

Mount Gibson Sanctuary is managed by the Australian Wildlife Conservancy. Mallee Cliffs National Park is managed by the New South Wales National Parks and Wildlife Service, and the reintroduction was carried out in partnership with the Australian Wildlife Conservancy.

The Greater Stick-nest Rat is listed as Vulnerable under Australian legislation, and a conservation advice provides a general frame for conservation response (DEWHA 2008).

Reintroductions to mainland sites have had limited success to date, in part because they have not been to prime chenopod habitat, have had competing herbivores and have not proven resilient to drought periods. Return of viable populations to the Australian mainland is a desirable conservation goal, but this is most likely to succeed at a large site with extensive high-quality habitat, in which introduced predators are excluded, impacts of native predators are constrained (e.g., through provision of artificial shelters, training of predator-naïve animals), potential competitors are effectively managed, underground refuges are available to escape extreme heat and some resources are provided in drought periods.