It’s a native animal with an image crisis. The water rat – an Australian mammal – is often mistaken for its introduced cousins, the black rat and brown rat.
The Australian water rat behaves more like an otter and has a positive and important role to play in the floodplain ecosystem. At Burrawang, near Condobolin, there are increasing signs of water rat activity and sightings of the water rats themselves. Senior Wetlands and River Conservation Officer Paul Packard said the discovery was good news for the region.
The presence of water rats is a good indicator of ecosystem health. It means that the food web is rebuilding and able to support the higher order predators.” he said.
A series of environmental watering events assisted the return of the water rats. The latest occurred over winter/spring with 250 megalitres delivered to the lagoon on the mid-Lachlan to maintain refuge values and restore ecosystem health.
We had seen evidence of old abandoned nests, but no live water rats. That has now changed with the animals returning to the banks of the mid-Lachlan to nest and feed. The water rat is an opportunistic carnivore and eats a range of foods including freshwater mussels, yabbies, fish and worms. Environmental water has allowed us to restore the habitat and the food web these mammals require to thrive,” Mr Packard said.
Water rat profile:
The water rat (Hydromys chrysogaster) is also known by its indigenous name – rakali. It is a member of the Muridae family, in the genus Hydromys.
It is one of only two amphibious mammals native to Australia – the other is the platypus. The water rat forages along the shore and underwater and builds its burrow along the river bank.
They were once common in Australia but their population declined as a result of altered flow regimes, hunting, loss of habitat and predation.
Mature water rats are markedly larger than introduced black and brown rats and can be distinguished by their partially webbed hind feet, thick white-tipped tail, small ears and blunt nose.