Ornithorhynchus anatinus


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Ornithorhynchus anatinus
Species Authority: (Shaw, 1799)
Common Name(s):
English Platypus, Duck-billed Platypus
French Ornithorynque

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor(s): Lunney, D., Dickman, C., Copley, P., Grant, T., Munks, S., Carrick, F., Serena, M. & Ellis, M.
Reviewer(s): Lamoreux, J. & Hilton-Taylor, C. (Global Mammal Assessment Team)
Listed as Least Concern in view of its wide distribution, presumed large population, and because it is unlikely to be declining at nearly the rate required to qualify for listing in a threatened category. There are, however, insufficient data at the catchment and local levels to predict population trends reliably in the long term.

Geographic Range [top]

Range Description: The Platypus is endemic to Australia, where it is dependent on rivers, streams, and bodies of freshwater. It is present in eastern Queensland and New South Wales, in eastern, central, and south-western Victoria, throughout Tasmania, and on King Island. An introduced population is established at the western end of Kangaroo Island (Carrick et al. 2008). Its occurrence is reasonably continuous within some catchments, but discontinuous in others (e.g., the Bega River catchment in New South Wales; Lunney et al. 1998), and in many catchments its actual distribution is poorly known. In Victoria, fewer than 200 individuals occupy the Wimmera-Avon River basin (distributed over an area of >2,400,000 ha), and the species appears to have recently become extinct in the neighbouring Avoca River basin (Australian Platypus Conservancy, unpublished data) (T. Grant, S. Munks, F. Carrick, and M. Serena pers. comm.). The species now appears to be extinct also from its former range in the Adelaide Hills and Mount Lofty Ranges in South Australia.
Australia (New South Wales, Queensland, South Australia, Tasmania, Victoria)
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: It is a common species. Its overall distribution appears to be little changed from its historical distribution (except in South Australia). However, many local populations are known to have declined or disappeared within the last few decades, and in general there is a surprising lack of knowledge about its abundance (T. Grant, S. Munks, F. Carrick, and M. Serena pers. comm.). Specifically, there are insufficient data at the catchment and local levels to predict population trends reliably in the long term.
Population Trend: Unknown

Habitat and Ecology [top]

Habitat and Ecology: The Platypus is restricted to streams and suitable freshwater bodies, including some shallow water storage lakes and ponds (Carrick et al. 2008). Its food is almost exclusively benthic macroinvertebrates and so the species is water-dependent. Platypuses are largely solitary, and when not foraging in water they normally occupy a resting or nesting burrow in earth banks, although some individuals have been found resting in accumulated stream debris or in low dense vegetation. The species is seldom observed moving on land in mainland Australia, but is frequently seen out of the water in Tasmania, where its predator, the fox (Vulpes vulpes), has been introduced only relatively recently (T. Grant, S. Munks, F. Carrick, and M. Serena pers. comm.). The breeding season varies widely depending on location. Females produce one to three eggs annually, but usually two (Carrick et al. 2008). Platypuses are long-lived animals (up to 20 years in the wild).
Systems: Terrestrial; Freshwater

Threats [top]

Major Threat(s): Currently, the predominant threat to the species on the mainland is reduction in stream and river flows due to recent successive droughts, stream regulation, and extraction of water for agricultural, domestic, and industrial supplies. It is also at risk from the opposite extremes associated with climate change – extensive flooding both in space and time associated with recent tropical cyclones that have resulted in increased mortality and all but eliminated recruitment in 2006 over a substantial part of the species’ northern range. Habitat modification due to bank erosion and stream sedimentation (as a result of poor land management practices in agriculture, forestry, and urbanization) are also of great concern. In the case of urban streams, Platypus populations may be adversely affected both by poor water quality (in the form of suspended solids and nutrient enrichment) and contamination of sediment by heavy metals (Serena and Pettigrove 2005). Accidental drowning in nets and traps set for fish and crustaceans has the potential to impact Platypus distribution and abundance in all parts of its range, especially in small streams where populations may be critically small.

Conservation Actions [top]

Conservation Actions: Conservation of the Platypus is limited to its listing as a legally protected species in all states in which it occurs and its incidental inclusion in some national parks and reserves. Legislation prohibiting or controlling problematic fishing activities has been enacted in New South Wales and Victoria, but regulations concerning illegal netting and trapping are often poorly enforced. The most widespread field monitoring program for the species is in Victoria (Australian Platypus Conservancy). There are also a few system-specific studies in other states and community-based reporting of anecdotal occurrences of the species to a variety of institutional and private databases. Still more information about population numbers and monitoring are crucial, especially for a long-lived species such as the Platypus where a lack of recruitment can be masked until a dramatic population crash occurs as adults reach the end of their lifespan.

Population studies of fragmented populations should be a research priority, together with studies to help verify the current distribution and baseline population parameters in areas where the species has declined (Grant and Temple-Smith 2003). Once the Platypus becomes extinct in a river system, the likelihood of its re-colonising that system without human intervention is minimal (T. Grant, S. Munks, F. Carrick, and M. Serena pers. comm.). One reintroduction program is underway in a single fire-affected stream in Victoria (Australian Platypus Conservancy).

Some populations of Platypuses have exhibited antibodies to Leptospirosis, probably transmitted via cattle, but no clinical symptoms have been observed. Mortality from an ulcerative dermatitis caused by Mucor fungus, however, has been recorded in at least one river system in Tasmania. There is currently no active investigation of this disease, which should be a research priority both in that state and on the mainland where the fungus is also found (T. Grant, S. Munks, F. Carrick, and M. Serena pers. comm.).

Citation: Lunney, D., Dickman, C., Copley, P., Grant, T., Munks, S., Carrick, F., Serena, M. & Ellis, M. 2008. Ornithorhynchus anatinus. The IUCN Red List of Threatened Species. Version 2014.3. <>. Downloaded on 22 December 2014.
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