The Greater Stick-nest Rat (Leporillus conditor) is listed as Vulnerable under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) and under the WA Wildlife Conservation Act 1950.
The Greater Stick-nest Rat once ranged across semi-arid regions of southern Australia, however the species’ range declined rapidly after European colonisation. Further declines meant that by the 1930s, the Greater Stick-nest Rat was extinct on the Australian mainland, and today, the only natural population occurs on the Franklin Islands in South Australia.
Greater Stick-nest Rats are a large rodent, ranging from 17-26cm in body length and weighing up to 450g. They have fluffy yellow-brown to grey fur on their back and cream fur below. A blunt snout, large, dark eyes and large, rounded ears are also characteristic of the species. They also have a long tail that is dark brown above and light brown below, and distinctive white markings on their upper feet. When resting, Greater Stick-nest Rats sit in a hunched position that is similar to the stance of a rabbit.
As their name suggests, Stick-nest Rats builds huge, communal nests out of available sticks. Groups of 10 to 20 individuals work together to find and drag branches to a central site – usually around a bush that becomes part of the final nest. Branches are chewed to length and woven together with additionally-collected green vegetation. These nests can be up to 1 metre in height and 1.5 metres wide. Tunnels lead from the outside to the centre of these structures, where the animals place grass and other soft green vegetation. These nests provide protection from native predators.
Greater Stick-nest Rats are herbivores, feeding on the leaves and fruits of a wide variety of plant species, with a preference for succulent and semi-succulent plants. Breeding can occur year-round, but usually peaks in autumn and winter. Females give birth to between one and three young. These young are well-developed at birth and secure themselves tightly to their mother’s teats. They are carried around by the mother for about a month, until weaning and independence.
Like most other small to medium-sized Australian mammals, Greater Stick-nest Rats are highly susceptible to predation by introduced foxes and feral cats. Introduced herbivores would have exacerbated population declines by competing for food and trampling nests.
Remaining and reintroduced populations on islands and in predator-free enclosures do not immediately face threats from introduced predators or herbivores, however, these populations are small and geographically isolated, and at risk of extinction from localised catastrophic events such as fire, disease, or incursions by feral predators.
The Australian Wildlife Conservancy (AWC) has reintroduced Greater Stick-nest rats to a five-hectare breeding enclosure at their Mt Gibson Reserve in the NACC NRM region. Animals from the enclosure will eventually be released into the 7,800 hectare Mt Gibson Endangered Wildlife Restoration Project area upon completion of the 40 kilometre-long predator-proof fence. AWC has previously introduced Greater Stick-nest Rats to their Scotia Wildlife Sanctuary and Faure Island. The Scotia population is considered extant, but attempts to monitor known nest sites have been hindered by other reintroduced species. The reintroduction to Faure Island was not successful. Another attempt will be made in the future, building-on the experience of the reintroduction to Mt Gibson.
Fast fact
Did you know that the Greater Stick-nest Rat had a smaller nest-building relative: the Lesser Stick-nest Rat – which is now almost certainly extinct. Recently, a jaw bone of a long-deceased Lesser Stick-nest Rat was found in a cave on AWC’s Mt Gibson Sanctuary.
Information Source: Government of Australia, Department of Environment and Energy; WA Department of Biodiversity, Conservation and Attractions; and Australian Wildlife Conservancy.