Scientific Name: Hydromys chrysogaster
Conservation Status: Common
Length: 23–37 cm
Weight: 340–1275 g
Gestation: 24–34 days
Number of young: 3–4
Distribution: East, northern and south-western Australia and Papua New Guinea
Habitat: On the banks of lakes, streams and other bodies of water
Description: Apart from the platypus, the Water Rat is the only amphibious land-based Australian mammal. It has broad, partially-webbed hindfeet, water-repellent fur and many whiskers. The Water Rat varies in colouration from brown to grey-brown or black on its back with a pale belly. The tail is long, sparsely haired and 22–32 cm long. Males are slightly larger than females.
Diet: The Water Rat is a carnivore and eats aquatic insects, fish, crustaceans and mussels. Frogs, lizards, small mammals and water birds might also be eaten.
Behaviour: Unlike many Australian rodents, the Water Rat is not entirely nocturnal. It is most active around sunset and has been seen foraging during the day. They are slightly clumsy on land and can climb hollow trees in search of prey. However, they prefer to catch their prey in the water.
Threats: Snakes and large fish are natural predators of young Water Rats while birds of prey and cats hunt both adult and young Water Rats.
Water Rats are an important indicator of aquatic ecosystem health. Drought and habitat degradation are threats to their continued survival. They were heavily hunted for their pelts in the 1930s and 1940s until they became a protected species.
At Perth Zoo: You can see Perth Zoo’s Water Rats in the Nocturnal House.
Join the Perth Zoo-coordinated Night Stalk from 1 September to 16 October and spotlight for native animals in your local bushland. Night Stalk is a great way to become involved in community conservation action and to learn about our native animals, their habitat and their threats. Night Stalk is sponsored by Tronox.
Watch a video about the release of Native Water Rats at the Australian Wildlife Conservancy’s Karakamia Wildlife Sanctuary as part of Perth Zoo’s Urban Renewal program: