Rakali | wwf
Rakali, water rat. 
	© Tracy Oliver
Citizen Scientists help unravel the secret life of rakali

WWF-Australia, in partnership with the WA Department of Parks and Wildlife conducted a widely promoted rakali community survey in Western Australia. The aim of this survey was to obtain valuable information on the distribution of rakali in WA and to identify threats to this species, while at the same time educating the community about this cryptic and often misunderstood native rodent.

A total of 234 sightings were reported over four months (December 2014 to March 2015). Additionally, 49 transect surveys were carried out with the help of over 90 community volunteers, looking for characteristic rakali foot prints and feeding middens (“the Rakali Walk”).  

The study has found that the range of rakali has contracted towards the coastal areas of the south-west and we identified areas of localised declines in the Perth Metropolitan Area. The drying climate in association with water extraction and habitat degradation are a major threat to rakali. Additionally, we found that drowning in box or opera-house freshwater crayfish (e.g. marron, Cherax cainii) traps were the main reported cause of rakali mortality.

The Rakali Community Survey report has highlighted critical research and management recommendations for the species and will inform future conservation strategies for this fascinating species.

The Rakali Community Survey was made possible thanks to a grant from Lotterywest.
Rakali, water rat. 
	© Barbara Wilson / DPaW
Rakali, water rat.
© Barbara Wilson / DPaW
  • Common name

    Rakali, Australian water-rat, Moytj or Ngurju (Southwest Australia Noongar Aboriginal names)

  • Scientific name

    Hydromys chrysogaster

  • Habitat

    The rakali is one of the few amphibious (semi-aquatic) mammals in Australia. Rakali are found in both fresh and marine waters, including riverine, wetland, estuarine and coastal habitats in all Australian states and territories.

  • Weight

    Between 300g to 1.3kg

  • Appearance

    Rakali can be distinguished from introduced black rats by their broad face, larger size (a rakali’s body length is about 30 cm compared to a black rat of no more than 20 cm) and the rakali’s characteristic thick tail that ends with a white tip. They are black to grey on their backs with white to golden fur on their bellies. Adaptations to their semi-aquatic lifestyle include partially webbed hind-feet, dense water-repellent fur and small ears and eyes.

  • Did you know?

    •The rakali or water rat is a native Australian rodent – not a marsupial like a wallaby or a bandicoot. Almost a quarter of all native Australian mammals are rodents!
    • Rakali are notoriously difficult to study and are probably one of the least known native mammals. 
    • They are semi-nocturnal species, more easily observed at sunset and sunrise, but can occasionally be seen foraging during the day. 
    • The water rat is an opportunistic predator feeding on a wide range of prey including insects, frogs, fish, crustaceans, mussels and even small mammals and birds. Food is often carried to a feeding platform on the bank for consumption. The small piles of shell and crayfish fragments form characteristic ‘feeding middens’. 
    • Because rakali rely on a good supply of invertebrate prey, the presence of rakali is considered to be an indicator of good riverine and wetland health. 

© David Judge © WWF-Aus / Rebecca Boyland © David Judge © Tim Gamblin © Bert and Babs Wells, Parks and Wildlife © WWF-Aus / Sabrina Trocini © Tim Gamblin © Tim Gamblin © Tim Gamblin © Paul Mutton