The rakali was widely trapped for its fur in the 1930s and early 1940s (Watts and Aslin 1981). The species is now considered to be nationally secure and has been assigned an international conservation status of “Least Concern”. However, abundance is often low and these animals are also naturally quite short-lived. Some populations may therefore be locally or regionally threatened (Bettink 2016).
Rakali mortalities in Victoria (from 2001-2017) and southwestern Western Australian (from 2014-2015) reportedly most often occurred due to drowning in fish nets (including those used by commercial eel fishers) or enclosed traps targeting crabs or crayfish/yabbies, predation (mainly by foxes, dogs and cats), and being run over by motor vehicles (Trocini et al. 2015; Williams and Serena 2018). Because a rakali feeds mainly in or near water, numbers may also drop considerably during droughts, particularly if reproduction fails widely in three consecutive dry years (Williams and Serena 2018). The practice of lining irrigation channels with plastic as a water-saving measure can also have devastating consequences for this species (Williams and Serena 2018).
Rakali can annoy humans by raiding ornamental goldfish ponds or poultry runs, stealing fish bait, depositing piles of fish bones on a boat or leaving the gory remains of cane toads near swimming pools. However, killing or relocating these animals is illegal and can result in hefty fines. These actions are also rarely effective as a permanent control measure, because juveniles quickly recolonise suitable habitat.
A more sustainable solution is to learn to co-exist with this clever and attractive native mammal, for example by using wire netting to exclude rakali from a fish pond.
It’s also possible to take positive conservation action on behalf of this species, for example by ensuring that new wetlands created as part of housing estates, sporting facilities or the like are designed to be rakali-friendly. To help achieve this outcome, the APC has produced guidelines providing practical advice to organisations such as management agencies and local councils – click here for Guidelines for Design of Rakali-friendly Wetlands.
Photos courtesy of Ken Mival (top) and Andrew Fishman (bottom)
LITERATURE CITED
Bettink KA (2016) Shedding light on rakali: genetic and morphological differentiation in the Australo-Papuan goldenbellied water rat (Hydromys chrysogaster), with notes on the Barrow Island population. PhD Thesis, University of Western Australia, Nedlands.
Trocini S, Barrett G, Howard K and Ramalho C (2015) Rakali community survey 2014-2015. Report by WWF Australia and WA Department of Parks and Wildlife. WWF Australia: Perth, WA.
Watts CHS and Aslin HJ (1981) The Rodents of Australia. Angus & Robertson: Sydney.
Williams G and Serena M (2018) Distribution of the Australian water-rat Hydromys chrysogaster in Victoria: findings from community-based sightings and live-trapping surveys. The Victorian Naturalist 135, 71-83.