Magpie Goose (Anseranas semipalmata) Fact Sheet: Population & Conservation Status

Population estimates

• Approximately 3.5-5 million individuals (Tulloch and McKean 1983; Carboneras and Kirwan 2017)
  • Populations fluctuate substantially (Carboneras and Kirwan 2017)
    • Stability noted in some regions (e.g., Bayliss and Yeomans 1990)
  • Bayliss and Ligtermoet (2017) report approximate 20-year decadal cycles, influenced by rainfall and river/stream flow patterns
    • These were influenced by global climate patterns, specifically the interaction between ENSO and the Pacific Decadal Oscillation (PDO)
• Population recovery aided by introductions in some regions (Carboneras and Kirwan 2017)
  • Victoria
  • New South Wales
  • South Australia
• Future projections
  • Populations may be severely affected by loss of wetland habitat due to climate change-induced sea level rise in the next 200-300 years (Traill, Bradshaw, Delean, et al. 2010; Bayliss et al. 2017; Pettit, Bayliss, Bartolo 2017)
  • Also see Threats to Survival, below
• Historical notes (Nye et al. 2007; Carboneras and Kirwan 2017, and as noted)
  • 1800s
    • Nested extensively in southeastern Australia
    • Large declines due to loss of wetland habitat and hunting
      • Also, poisoning, predation by red foxes (Vulpes vulpes), and drought
  • Early 1900s
    • Nearly disappeared from southeast Australia (Olsen 2010)
      • Causes
        • Wetland damage and drainage
        • Overhunting

Population structure

(Roshier et al. 2012)

• Connectivity exists among populations
  • Genetic interchange between northern Queensland and southern New Guinea, across the Torres Strait
• Genetic variability introduced from Cape York population
• Some differentiation between northern Australia and New Guinea
  • Degree of differentiation not clear
    • Requires further investigation

IUCN

(BirdLife International 2016)

• Least Concern (2016 assessment)
  • Large range
  • Large population size
• Population trend
  • Stable but likely fluctuating
• Previous assessments
  • 2012: Least Concern
  • 2009: Least Concern
  • 2008: Least Concern
  • 2004: Least Concern
  • 2000: Least Concern
  • 1994: Lower Risk/least concern
  • 1988: Lower Risk/least concern

CITES

• Not listed (UNEP 2020)

Government laws and regulations

• Protected across Australia (Delaney et al. 2009)
  • Federal
    • Listed as a marine protected species under Environment Protection and Biodiversity Conservation Act 1999
    • Export of birds or their parts requires a permit
  • Northern Territory
    • Protect species under Territory Parks and Wildlife Conservation Act
  • New South Wales
    • Listed as vulnerable
  • Victoria
    • Listed as threatened
  • Southern Territory
    • Listed as endangered
• History of protection
  • 1920s
    • Partial protection from recreational hunting (Nye et al. 2007)
  • 1930s
    • Full protected from hunting (Carboneras and Kirwan 2017)

Main threat

• Loss of floodplain habitats due to rapid colonization and spread of non-native grasses (Bayliss et al. 2017)
  • Compounded by impacts of feral pigs

Habitat loss

• This species requires specialized marsh vegetation for breeding (Johnsgard 1978)
• Threats to breeding areas (Carboneras and Kirwan 2017, and as noted)
  • Settlement and development in floodplains (and other catchments)
  • Draining and damming
  • Crowding out of native aquatic plants used by Magpie Geese by non-native aquatic grasses (e.g., para grass Urochloa mutica and olive hymenachne Hymenachne acutigluma) (Setterfield et al. 2013)
  • Crowding out of native plants by non-native shrubs (e.g., Mimosa) (Bayliss and Yeomans 1990; Whitehead and Saalfeld 2000)
  • Feral ungulates (currently pigs and historically water buffalo)
  • Rice growing
  • Uranium mining on Kakadu National Park
  • Grazing or trampling of plants by feral animals
    • See Interspecies Interactions
  • Silt and saltwater intrusion into freshwater wetlands
    • Sources:
      • Damaged levees
      • Longer-term sea level rise (Traill, Bradshaw, Delean, et al. 2010; Pettit, Bayliss, Bartolo 2017; Bayliss et al. 2017)
  • Climate change (Nye et al. 2007; Traill, Whitehead, et al. 2009)
    • Variable rainfall will reduce food availability and refuge space during droughts
      • Loss of refuge space during droughts
    • Likely to cause increases in diseases
• Populations in southeastern Australia (Carboneras and Kirwan 2017)
  • Water management practices limit habitat for breeding and drought refuge

Hunting

• Protected in most parts of Australia (Carboneras and Kirwan 2017)
• Legally hunted in the Northern Territory (Carboneras and Kirwan 2017)
  • Most important game bird (Whitehead et al. 1988, except as noted)
    • Comprises approximately 80% of hunting take (self-reported survey data)
    • Considered fair eating, despite a “musky smell” (Delacour 1954)
• Up to 18% of total population taken annually (Carboneras and Kirwan 2017)
  • 130,000-360,000 birds per year (Carboneras and Kirwan 2017, except as noted)
    • Many taken by Aboriginal peoples
      • Unregulated
        • Considered sustainable (Delaney et al. 2009)
      • Estimated take of birds: maximum of 60,000 (Delaney et al. 2009, citing A. Griffiths REATAS unpublished data)
        • Brook and Whitehead (2005a) estimate 50,000-150,000 birds per year
      • Estimated take of eggs: unknown (Delaney et al. 2009)
      • Contributes as much as $1.2 million per year to Northern Territory’s economy (Delaney et al. 2009)
    • Some taken for recreation (non-Aboriginal hunters)
      • About 20,000-40,000 birds per year (Brook and Whitehead 2005a; Delaney et al. 2009)
      • Contributes about $400,000-800,000 to Northern Territory’s economy (Delaney et al. 2009)
• Currently, no commercial demand for birds or eggs (Delaney et al. 2009)
• Other types of hunting
  • Hunted in farming areas (by permit only), where geese visit pastures and rice fields (Delaney et al. 2009; Carboneras and Kirwan 2017)
    • Perceived as a pest (detrimental to crops)

Poisoning

• Magpie Geese accidentally ingest lead shotgun pellets or pellet fragments (Carboneras and Kirwan 2017)
  • Particularly prone because they dig holes while searching for corms (Whitehead and Tschirner 1991a; Nye et al. 2007)
• Concerted effort by hunters to reduce use of lead ammunition (Peter Bayliss, personal communication, 2018)
• High mortality rates (Harper and Hindmarsh 1990; Whitehead and Tschirner 1991a)
  • Lead may then be ingested by scavengers or predators (in the case of weakened/incapacitated birds)
• Many Magpie Geese affected, even within protected areas (Whitehead and Tschirner 1991a; Carboneras and Kirwan 2017)
  • Significant conservation problem in southern and southeastern Australia (Harper and Hindmarsh 1990; Nye et al. 2007)
    • Populations are small and recovering
    • In 1986, one population was reduced by 44% in three months (Harper and Hindmarsh 1990)
• Other poisoning
  • Historically, intentionally poisoned (Nye et al. 2007)
    • Rice-growers considered Magpie Goose to be pests
      • See History
      • See Interspecies Interactions

Predation

• See Predators

Adaptive management of wetlands

• Management of nesting areas (Morton et al. 1990)
  • Protection of plants needed for breeding (Wilson 1997; Whitehead and Saalfeld 2000)
  • Monitoring of non-native plant distribution (Delaney et al. 2009)
    • Aboriginal Community Ranger program to promote awareness of exotic plants
• Nine significant conservation reserves
  • About 30% of Magpie Geese nesting habitat is protected (Delaney et al. 2009)
  • Largest reserve, by far, is Kakadu National Park (Delaney et al. 2009)
    • About 70-80% of Magpie Geese dry season feeding refuges are protected on Kakadu National Park (Bayliss and Yeomans 1989)
      • These habitats are threatened by climate change-induced sea level rise and saltwater inundation (Bayliss et al. 2017)
    • One water chestnut swamp, Boggy Plain, has supported dry season feeding aggregations of 2-3 million birds or 70-80% of the NT population (Bayliss and Yeomans 1989; Pettit, Bayliss, Bartolo 2017)
• Use of non-lead ammunition by hunters (Whitehead and Tschirner 1991a)

Quotas on harvest

• Recreational take regulated by Australian government (Delaney et al. 2009; Northern Territory Government 2017)
  • Permit required
    • About 1,000-1,500 issued each year
• Population sizes fluctuate from year to year (Brook and Whitehead 2005a)
  • Population monitoring needed to assess/adjust sustainable harvest levels (Delaney et al. 2009; Northern Territory Government 2017)
• Also see Hunting

Reintroduction programs

• Used in southern and southeastern Australia (Nye et al. 2007)
  • Varying levels of success

Social importance of Magpie Geese to Australians

• Incorporate socio-ecological values into management and policy planning (see Bayliss and Ligtermoet 2017)

Magpie Geese are an important game bird, particularly for Aboriginal hunters.

This species is protected by the Australian Government but is legally hunted in the Northern Territory.

Population sizes can change substantially from year to year, so surveys are conducted frequently to prevent overhunting.

Image credit: © Geoff Whalan via Flickr, Creative Commons License BY-NC-ND 2.0. Some rights reserved.