Platypus (Ornithorhynchus anatinus) Fact Sheet: Population & Conservation Status

Population estimates

• Abundance difficult to quantify (Woinarski and Burbidge 2016)
  • Cryptic, nocturnal, aquatic
• Until recently, considered common over much of its range (except South Australia) (Grant 2015), but growing evidence of higher risk of declines and local extinctions than previously thought (Bino et al. 2019; Hawke et al. 2019; Bino et al. 2020)
  • Platypus has experienced large declines since 1890s (Hawke et al. 2019)
  • Today's populations thought to number in the thousands or tens of thousands (Grant 2015)
    • 30,000 to 300,000 (Woinarski and Burbidge 2016)
• No robust estimates of total population size (except Kangaroo Island) (Furlan et al. 2012; Grant 2015; Woinarski and Burbidge 2016, except as noted)
  • Lack of systematic, rigorous monitoring studies; some recent initiatives beginning to change this
    • No study of nearly half of the platypus's potential range (Hawke et al. 2019)
  • Localized declines may go undetected (Gust and Griffiths 2010; Woinarski and Burbidge 2016)
• Kangaroo Island
  • Approximately 110 individuals (Furlan et al. 2012)
• Population trends
  • Total population: declining (Woinarski and Burbidge 2016)
    • Population declines in all major mainland drainage basins (Hawke et al. 2019; see Fig. 1)
  • Large declines in Victoria and New South Wales (Grant 2015; Woinarski and Burbidge 2016)
  • Local declines and extinctions reported, especially in urban and agricultural areas (Grant 1992)
  • Uncommon reports of platypuses in South Australia (Grant 2007)
    • May be transient, non-breeding individuals

Population structure

• Platypuses in Tasmania/King Island genetically distinct from platypuses in mainland Australia (Furlan et al. 2010; Gongora et al. 2012)
  • Reflects long-term isolation of Tasmania from mainland Australia
    • Last common ancestor ~0.7-0.94 mya
  • Little genetic differentiation within Tasmania
• Regional differences among mainland platypuses (Kolomyjec et al. 2009; Furlan et al. 2013; Bino et al. 2015; Grant 2015)
• Genetic evidence of connectivity between coastal and inland areas separated by the Great Dividing Range (Furlan et al. 2013)
• Populations of low genetic diversity (Furlan et al. 2012)
  • King Island
  • Kangaroo Island
    • Introduced
• Some river systems act as discrete population units (Kolomyjec et al. 2009)
  • May still have gene flow between them
  • Also see Dispersal
• See more discussion by Bino et al. (2019)

IUCN

• Near Threatened (2014 assessment) (Woinarski and Burbidge 2016)
  • Justification
    • Extensive range
    • Large population size
    • Overall decline in population
      • Extent varies across the platypus’ range
      • Not thought to exceed 30% in the last three generations
  • Threats affect individuals and platypus habitat
• Bino et al. (2020) suggest downgraded status of Vulnerable, given future drought and watershed regulation impacts
• Previous assessments (Woinarski and Burbidge 2016)
  • 2008: Least Concern
  • 1996: Lower Risk/least concern

CITES

• Not listed (UNEP 2018)

Government laws and regulations

• Legally protected in Australian Capital Territory and all Australian states where it occurs (Grant 2007; Grant 2015)
  • Platypuses cannot be collected or killed, except for scientific research
  • Zoos and sanctuaries required to hold special licenses
  • Exports must be approved by the Federal Government
• Endangered status in South Australia (Grant 2015)
  • Unlisted in other Australian states and nationally (Bino et al. 2019)
• Additional threatened species listings on state and federal schedules advised by Bino et al. (2020)

Also see Grant and Temple-Smith (2003).

Habitat loss, degradation, and poor water quality

• Platypuses depend on streams, rivers, and bodies of freshwater (Grant 2015; Woinarski and Burbidge 2016; Bino et al. 2020, except as noted)
  • Vulnerable to poor land and watershed management practices
  • Unlikely to re-colonize a river system without human intervention (Grant et al., personal communication, 2014, as cited in Woinarski and Burbidge 2016)
  • Local populations strongly impacted by dam construction
• Urban streams pose challenges
  • Contain debris and heavy metals (Woinarski and Burbidge 2016)
    • See Booth and Connolly (2008) for discussion of PCBs
  • Stormwater runoff limits platypus distribution (Martin et al. 2014)
• Platypuses can show resiliency—survive and reproduce in degraded/modified habitats (Burbidge and McKenzie 1989; Grant 2007; Klamt et al. 2011)
  • However, require specialized habitat and have limited dispersal ability (Klamt et al. 2011)
  • May show preference for undisturbed streams (see Koch et al. 2006)

Drought and flood

(Grant 2015; Woinarski and Burbidge 2016, except as noted)

• Reduced habitat and water quality
  • Bank erosion
  • Sedimentation
  • Less food available (Serena et al. 2014)
• Reduced breeding success
  • River flooding during breeding season may displace young/juveniles from burrows, or some may drown (Serena et al. 2014; Serena and Grant 2017)

Climate change

• Increased severity of droughts and floods (Grant 2015; Bino et al. 2020)
  • Estimated to cause local extinctions in approximately 40% of the platypus's range by 2070
• Amount of suitable habitat may decrease by ~30% by 2070 (Klamt et al. 2011)
  • Distribution predicted to shift almost entirely south of Brisbane
  • Drying and less rainfall will cause loss of previously permanent water systems
    • Shallow water of poor quality not suitable as platypus habitat
• Increased air and water temperatures (Klamt et al. 2011)
  • Will likely impact platypus physiology
  • Cannot tolerate hot ambient temperatures, due to insulating fur
• Increased salinity of inland waters (Grant 2007)
  • Effects on physiology require investigation
    • Food abundance may decrease
    • May impair osmoregulation
    • May hinder use of electroreception
      • Electricity does not conduct as well in brackish/saltwater

Fishing

• Injured by and drown in fishing gear (e.g., lines, traps, nets) that targets freshwater fish and crayfish (Grant 2015)
  • Some gear types not permitted within the range of the platypus (Grant 2007)

Non-native predators

• Red fox, Vulpes vulpes (Grant 2007; Grant 2015)
• Domestic/feral dogs (Grant 2015)
• Feral cats (Woinarski and Burbidge 2016)
• No introduced predators on King and Kangaroo Islands

Other causes of death

• Entanglement and injuries due to trash and plastic debris and discarded fishing line (Grant 2007; Grant 2015)
• Hit by vehicles on roads (Whittington 1993a; Otley 2001; Grant 2015)

Historical threats

• Hunted for fur until about 1900 (Grant 2015)
  • Rugs, fashion muffs, capes/cloaks (Barrett 1941)
    • A single rug required 40-60+ pelts (Grant 2007; Bino et al. 2019)
  • Hats and slippers (Grant 2007)
  • See Bino et al. (2019) for discussion of fur sales and exports

Habitat

• Preserve and extend protected areas
  • The platypus occurs within national parks, reserves, and wildlife sanctuaries (Woinarski and Burbidge 2016)
• Protect and manage watersheds (Serena et al. 2014; Bino et al. 2019; Bino et al. 2020, and as noted)
  • Maintain connectivity among rivers (Furlan et al. 2013)
  • Construct wetlands to provide suitable habitat (Stannard et al. 2010)
  • Reduce and prevent erosion
  • Change river/stream flow and depth to benefit platypus
    • Greater substrate complexity
    • Creation of foraging and drought refuge pools
    • Managing urban stormwater runoff

Fishing regulations

• Enacted in New South Wales and Victoria (Woinarski and Burbidge 2016)
• Regulations related to illegal netting and trapping need better enforcement (Woinarski and Burbidge 2016)
• Bino et al. (2020) propose a national ban on enclosed crayfish traps

Monitoring

• Most widespread monitoring program administered by cesar (Josh Griffiths, personal communication, 2018)
  • Previously, Australian Platypus Conservancy (Woinarski and Burbidge 2016)
• cesar, San Diego Zoo Wildlife Alliance, and the University of Melbourne are partners in monitoring platypus populations, health, and habitat (San Diego Zoo Global Public Relations 2018)
• Some systematic, small-scale studies and community-based reporting (Woinarski and Burbidge 2016)
• Identification of evolutionarily significant population (genetic) units (Kolomyjec et al. 2009)
• Determination of dispersal capabilities, particularly under effects of climate change (Bino et al. 2019)

• cesar
• Australian Platypus Conservancy
• San Diego Zoo Wildlife Alliance
• Platypus Conservation Initiative (University of NSW)

The University of Melbourne, San Diego Zoo Wildlife Alliance, and cesar have teamed up to study and protect platypuses in the wild.

In this video, learn how DNA collected from freshwater creeks is helping scientists learn more about this rarely seen Australian mammal.

© San Diego Zoo Wildlife Alliance. All rights reserved.

Platypus in a creek in Tasmania.

Good watershed management is crucial in protecting the platypus.

Image credit: © Klaus via Flickr. Creative Commons BY-SA 2.0.