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Watching for Water Rats

Australian water-rats are active during the day as well as at night.  They are most often observed swimming on the surface, especially in the evening or early morning.


However, the animals also frequently emerge from the water to eat (sitting up and holding their meal in their forepaws) or run along the river bank or shore searching for food.  A feeding “table” consisting of a pile of yabby claws or mussel shells on a rock or log (or boat deck) is often the best clue that the species is present. 

Water-rats grow to about 50 to 70 centimetres in length (including their tail) and can weigh up to 1.3 kilograms.  The colour of the head and back may be nearly black (with golden-yellow belly fur) or some shade of brown or grey (with fawn- to cream-coloured belly fur).  In all cases, the tail has a conspicuous white tip


Mention the word "rat” and images of two introduced pests - the black rat and brown rat - spring to mind.  In fact, the Australian water-rat (Hydromys chrysogaster) is a native species that was a natural part of our environment long before its Eurasian rodent cousins arrived on ships carrying the early colonists. 

The water-rat (also known as rakali) is an extremely attractive animal which is found in most parts of Victoria.  Its ecological role is much the same as that of otters living on other continents.  The water-rat also has many otter-like features, including a thick coat of soft fur, a blunt and densely whiskered muzzle, partly webbed hind feet and a furry, tapering tail.

Water-rats are known to eat aquatic insects, yabbies, mussels, shrimps, and frogs (and even cane toads in northern Australia).  Their formidable set of teeth can also be used to kill fish, tortoises and water birds, occasionally up to the size of small ducks. 

Although water-rats are fully protected by law, many continue to die in submerged opera house nets and similar enclosed traps set for yabbies and freshwater crayfish.  Anglers are instead encouraged to use open lift-style nets or baited lines (without hooks) as inexpensive and effective methods for catching yabbies and crays.    

Australian water-rats occasionally come into conflict with humans when they raid fish farms, devour pet food left on suburban porches, steal bait from anglers, and leave piles of mussel shells on the decks of moored boats or the remains of cane toads around the edges of swimming pools.

Killing or relocating a “problem” water-rat is both illegal and subject to hefty fines.  In any case, such actions will almost certainly be ineffective given that dispersing juveniles are likely to occupy a vacant home range very quickly. 

A better solution is to learn to live with water-rats by rat-proofing areas where you don’t want the animals to go, and not leaving fish scraps or other food around that will attract them.

If you are experiencing problems with rakali, please let the Australian Platypus Conservancy know the details and we’ll do our best to help.  By sharing such information it should be possible to develop workable solutions to deal with unwanted behaviours.

Rakali is a difficult species to study and little is known about its current status and distribution.  However, there is considerable evidence that numbers have declined in many areas.  The Australian Platypus Conservancy is working in partnership with various management agencies to find out how water-rat populations are faring across Victoria.  Because rakali is a top predator, the information will also help to monitor the health of the state’s waterways.

You can make a vital contribution by reporting all sightings of water-rats (including if you find a dead one).  Simply email the date and location of any sighting with any additional comments to (or phone 03 5157 5568).  Sightings from the past are welcome (even if you can only provide an approximate date) as they often help to establish how populations may have changed over time.  Reports from areas outside Victoria are also welcome.  All information is entered on a secure database and is only used for conservation purposes.



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When did you see water-rats?

How often have you seen water-rats?

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Name of lake/creek/river/water body:

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If possible, provide a GPS reference, CFA map reference or description of location in relation to named roads or other public landmarks:

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Australian Platypus Conservancy

PO Box 22, Wiseleigh VIC 3885