page_title: Rakali
section_title: Nesting
hierarchical_section_title: Rakali / Behaviour and life history / Nesting
caption_attribution_description: English: Hydromys chrysogaster, known as a Rakali or Water rat.
context_page_description: The rakali, Hydromys chrysogaster, also known as the rabe or water-rat, is an Australian native rodent first described in 1804. The change to the aboriginal name Rakali was intended to foster a positive public attitude by Environment Australia. The Gunwinggu people of western Arnhem Land call this animal Yirrku.
  It is the only member of the genus Hydromys with a range extending beyond Papua New Guinea and Indonesian West Papua. Having adapted to and colonised a unique niche of a semiaquatic and nocturnal lifestyle, this species lives in burrows on the banks of rivers, lakes and estuaries and feeds on aquatic insects, fish, crustaceans, mussels, snails, frogs, birds' eggs and water birds. Rakali have a body 231–370 millimetres in length, weigh, 340–1,275 grams and have a thick tail measuring around 242–345 millimetres. Females are generally smaller than males but tail lengths are normally the same.They have partially webbed hind legs, waterproof fur, a flattened head, a long blunt nose, many whiskers and small ears and eyes.
context_section_description: The breeding behaviours are influenced by seasonal conditions. Under good seasonal conditions the solitary water rat comes together with their mate and may produce several litters (if young are removed will reproduce again within two months), but separate on the birth of the young. Limited information is available on home range, but suggests localised movement around the nesting sites and foraging areas. Rakali construct burrows dug into river banks but have also been documented building nests within sunken logs and reeds, in areas surrounded by roots and dense riparian vegetation for cover from predators.
  There is increasing evidence of altered nesting habitat with rakali using artificial shelters of drainage pipes, exhaust pipes in moored boats, and rubber tyres in human-modified areas. This occurs more frequently in high population density situations.
caption: Rakali: reeds offer protection from predators
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