Greater Stick-nest Rats build enormous wooden shelters larger than Wedge-tailed Eagle nests. We protect their largest population on mainland Australia.
Range and abundance
The Greater Stick-nest Rat (Leporillus conditor) was once found across much of the semi-arid and southern arid zone of Australia. By the 1930s, it was confined to only two islands off the South Australian coast, East and West Franklin Islands. It was reintroduced to the Arid Recovery reserve in 1999. The population at Arid Recovery is currently the only stable population of Greater Stick-nest Rats on the mainland.
The Greater Stick-Nest Rat is a large rodent, growing to 250 mm in length and can weigh almost 500 grams. They have yellowish brown to grey, fluffy fur on its back and creamy white fur on its belly. They are also characterised by a blunt snout, large, dark eyes and rather long ears. Their tails are long, dark brown on top and lighter brown underneath.
Greater Stick-nest Rats are best known for their ability to build themselves homes out of sticks. The nest is generally built around a bush and sticks and branches are dragged to the site and woven together to create the nest. Large branches are gnawed to size and added to the nest. The nests can be up to one meter high and two metres wide. Tunnels are built from the outside to sleeping sites within the nest which consist of grass and other soft vegetation. These nests provide protection from native predators such as eagles and dingoes.
Greater Stick-nest Rats are herbivores, feeding mainly on the leaves, fruit and seeds of many different plant species. Stick-nest Rats do not need to drink water as they receive enough from the food that they eat. But since they need alot of water to survive extreme temperatures, they need to eat alot of plants with high water content to survive, such as the bladder saltbush. As such plants are also favoured by other herbivores like rabbits and Burrowing Bettongs, they are quite susceptible to overgrazing by such species.
Bladder saltbush: favourite food of Stick-nest Rats
Baby Greater Stick-nest Rats attach themselves firmly to their mother’s teats. They are then dragged along underneath her. This continues until they are weaned (stop drinking milk) and are able to care for themselves at about one month of age. Breeding can occur in any month of the year. At Arid Recovery, however this usually happens only in the cooler months of autumn and winter. Gestation is 30-40 days and 1-3 young are usually born.
Stick-nest rats are particularly vulnerable to predation by feral cats and foxes. As early as 1900, these animals became very rare and before long were extinct on the mainland. Fortunately, a population survived on the Franklin Islands off the South Australian coast.
What is Arid Recovery doing?
In 1998 we trialed a release of eight Greater Stick-nest Rats into Arid Recovery. The trial was a success, and plans were made for a larger release. So in 1999, we sourced 100 of them from Reevesby Island in Spencer Gulf South Australia, were the first native animal to be reintroduced back into the Arid Recovery Reserve. Since then the population has remained secure and there are now an estimated 250 Greater Stick-nest Rats within the reserve. There are currently an estimated 70 nests at the Arid Recovery Reserve with new nests being discovered all the time.
The success of this reintroduction has contributed to the Greater Stick-nest Rat’s national status being downgraded from endangered to vulnerable. However, Stick-nest Rat’s remain dependent on feral cat and fox free islands and fenced reserves like Arid Recovery. Without these refuges, the species would rapidly vanish from existence.
The Elusive Stickies
Since their reintroduction in 1999 the Greater Stick-nest Rat has remained quite elusive. They are hard to trap due to the very abundant Burrowing Bettongs (Bettongia lesueur), who disturb any traps that are set. We had to come up with unique methods to out-trick Burrowing Bettongs, like the ‘ratstaurants’. They look a bit like a top hat made of 50mm chicken wire mesh and pegged into the ground with droppers. The Stick-nest Rats can squeeze through the mesh but the Bettongs can’t dig under. Place an Elliot trap with a nutritious and healthy treat of carrots inside the ratstaurant and bingo! You can catch Stickies and not Bettongs. To read more about the unique methods are researchers use to study Greater Stick-nest Rats see this blog.
Written by Rachael Loneragan (March 2017)