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Radjah Shelduck (Rajah rajah) Fact Sheet: Population & Conservation Status

Population Status

Population estimates

  • R. r. radjah
    • About 10,000 to 100,000 individuals (Carboneras and Kirwan 2018)
  • R. r. rufitergum
    • Tentatively estimated at 150,000 individuals (Carboneras and Kirwan 2018)
  • Distribution-wide, considered fairly uncommon (Carboneras and Kirwan 2018)
    • May be locally common (e.g., lowland wetlands) (Callaghan and Green 1993; Pratt and Beehler 2014)
    • Said to be “fairly numerous” on some Maluku (Moluccas) Islands (British Ornithologists’ Union 1986; Carboneras and Kirwan 2018)

Population trend

  • Overall trend: decreasing (Birdlife International 2016; Wetlands International 2018, except as noted)
    • Some populations stable
      • Common in at least half of its historical range (Garnett and Crowley 2000)
  • Local declines in areas of human settlement, agriculture, mining, or road construction (Frith 1967)

Population structure

  • Presumed limited genetic exchange across the Torres Strait (Garnett and Crowley 2000)

Conservation Status

IUCN Status

  • Least Concern (2016 assessment) (Birdlife International 2016)
    • Large geographic range
  • Previous assessments (Birdlife International 2016)
    • 2012: Least Concern
    • 2009: Least Concern
    • 2008: Least Concern
    • 2004: Least Concern
    • 2000: Unknown
    • 1994: Unknown
    • 1988: Unknown

CITES Status

  • Not listed (as of Oct 2018) (UNEP 2018)

Government laws and regulations

Threats to Survival


(Carboneras and Kirwan 2018)

Loss of habitat

  • Local populations decrease where human settlement, agriculture, mining, and road construction occur (Frith 1967)
  • Rice cultivation in Northern Territory may be a major threat (Carboneras and Kirwan 2018)

Management Actions

Population monitoring

  • Abundance counts on major wetlands (Garnett and Crowley 2000)

Health of Populations

Radjah Shelduck swimming; reflection in blue water

Radjah Shelducks are considered fairly uncommon in the wild.

While some wild populations are stable, others are in decline due to land development and mining.

Image credit: © San Diego Zoo Global. All rights reserved.

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