Magpie Goose (Anseranas semipalmata) Fact Sheet: Behavior & Ecology

General

• Most active early morning and late afternoon (Frith 1967)
• Roost at night (Frith 1967)

Feeding

• Usually feed twice a day (Frith and Davies 1961)
  • Morning
    • Fly from roosts to feeding areas at dawn
    • Return to lagoon edges after a couple of hours
    • Spend more time feeding during the dry season
  • Late afternoon
    • Fly to feeding areas
    • Return to roost at dusk
    • Often move to feeding areas earlier on cooler/rainy days
  • Night
    • If disturbed, may feed at night instead of during the day
• When wild rice is abundant, may feed intermittently, all day (Frith and Davies 1961)

Highly mobile

• Frequently move within a floodplain and among floodplains (Morton et al. 1990)
• Large flocks break into smaller groups for feeding and roosting (Davies 1963)
  • Densities more concentrated during the dry season (Carboneras and Kirwan 2017)
• May move long distances in search of water, food, and breeding sites, especially during the wet season (Frith and Davies 1961; Traill, Bradshaw, and Brook 2010; Carboneras and Kirwan 2017, except as noted)
  • Not truly migratory
  • Seek nesting habitat in the early wet season and feeding areas in the dry season (Morton et al. 1990; Peter Bayliss, personal communication, 2018)
  • May move farther and more inland during drought
  • In one study, longest linear distance traveled was 114 km (71 mi) over 38 weeks
• Adults usually move farther than subadults (Traill, Bradshaw, and Brook 2010)
• Some birds remain or return to the same area after many years (Frith 1977)
• Occasional reports outside normal range (Carboneras and Kirwan 2017)
• Evidence of a flyway between northern Queensland and southern New Guinea across the Torres Strait (Roshier et al. 2012; Carboneras and Kirwan 2017)

Social relationships

• Form strong breeding group bonds (male–female, or male and 2-3 females) (Johnsgard 1961; Johnsgard 1965; Carboneras and Kirwan 2017)
  • Similar to geese and swans
  • Thought to be lifelong
• Dominance within a breeding group
  • Male is dominant to female(s) (Davies 1963; Frith 1967)
  • One female is dominant to other female(s) (Marchant and Higgins 1990)
• Persistent calling behavior observed in flocks (Marchant and Higgins 1990)
  • May aid group cohesion

Aggregations

• Form large flocks on floodplains (Bayliss and Yeomans 1990; Morton et al. 1990; Traill and Brook 2011, except as noted)
  • Feeding aggregations and large nesting colonies typically form at the start of the wet season (Peter Bayliss, personal communication, 2018)
  • Flocks are composed of breeding groups (Davies 1963; Frith 1967)
    • Breeding group membership stable, but composition of the larger flocks changes (Frith 1967)
• Benefits of aggregation behavior
  • Improved foraging for corms (e.g., Eleocharis) (Traill and Brook 2011)
  • Protection
    • Of eggs from predators during the wet season (Peter Bayliss, personal communication, 2018)
    • When alarmed, cluster together and quickly walk away from potential danger (Davies 1963; Frith 1967)
      • May take flight, if very alarmed
      • Goslings also group together when fearful
• Flock density
  • Individuals spaced out within the flock (Davies 1963)
    • Maintain “personal distance”
  • Daily patterns
    • Breeding groups disperse to feed and to roost (Frith 1967)
      • Attracted to aggregations they fly over
    • Attracted to larger groups on the ground or in flight (Marchant and Higgins 1990)
  • Seasonal patterns
    • Density of Magpie Geese higher around permanent or semi-permanent bodies of water (Bayliss and Yeomans 1990; Delaney et al. 2009)
      • High from June to October (Traill, Whitehead, et al. 2009)
        • Especially concentrated during late dry season, October-November (Delaney et al. 2009)
    • At onset of wet season, disperse across floodplain (Bayliss and Yeomans 1990; Delaney et al. 2009)
      • Densities increase again as breeding colonies form
    • Group size decreases when dry season ends and corms become less available (Traill and Brook 2011)
• Sex ratios (Davies 1963; Marchant and Higgins 1990)
  • Non-breeding season
    • Approximately 1:1
  • Breeding season
    • Females outnumber males in breeding colonies
    • Males outnumber females in non-breeding colonies
• Colony size
  • Up to 42 km² (16 mi²) (Frith and Davies 1961)
• Geographical differences in abundance
  • Immense flocks (“colonies”) in the Northern Territory of Australia (Morton et al. 1990)
    • Frith (1967) states up to 80,000, but about 5,000 is more typical
    • Morton et al. (1990) report floodplain systems with 80,000-350,000 individuals present
      • Perhaps as high as 500,000 individuals
  • New Guinea
    • Up to 10,000 individuals in a group (Carboneras and Kirwan 2017)

Flight groups

(Peter Bayliss, personal communication, 2018)

• Flying between feeding and roosting areas
  • About 200-300 individuals
• Largest groups
  • Thousands of individuals or more

Roosting

• Habitats
  • Dry banks on marsh edges (Morton et al. 1990)
  • Trees in wet woodlands (Frith and Davies 1961; Marchant and Higgins 1990)
  • On water in deep wetlands (Frith 1967; Marchant and Higgins 1990)
• Daily patterns
  • Roost at night and between feeding bouts (Marchant and Higgins 1990)
• Fidelity to roost site
  • Breeding groups do not roost in the same place each night (Frith 1967)
• Seasonal patterns
  • Dry season (Bayliss and Yeomans 1990)
    • Roosting and feeding areas occur

Vocalizations

• Adults
  • Loud, resonant honks (Frith 1967; Carboneras and Kirwan 2017)
    • Given as spaced calls or in rapid succession
    • Honks of female of higher pitch than male
    • Females typically return calls of male in breeding group
  • “Uplift Call” (Davies 1963; Carboneras and Kirwan 2017, except as noted)
    • Functions
      • Defense of territory
      • Advertising status (Marchant and Higgins 1990)
    • Posture
      • Upright stance
      • Bill jerked upward, while giving single honks
        • Bill movements may sometimes be absent
    • Often given by male
  • “Alarm Call” (Carboneras and Kirwan 2017)
    • Similar to Uplift Call, but more insistent
    • Very high pitched when distressed
    • Posture
      • Alert
  • “Concert Calls” (Davies 1963; Carboneras and Kirwan 2017)
    • Stretch neck, open and close bill, and vocalize
      • Rapid, repeated honks
        • Can become trill-like
    • Given as duet between family members
      • Adults and young
    • Functions
      • Greeting
      • Breeding pair formation and bonding
      • Threat/aggression
      • Display after successful defense of territory
      • Prior to flight
  • Hissing (Johnsgard 1961)
    • Functions
      • Defense of nest
    • Given by male
      • Accompanied by rapid open/close of bill and raised feathers
• Goslings and juveniles
  • High, hissing whistles when begging for food (Carboneras and Kirwan 2017)
  • Chittering noises made by rapidly opening and closing bill (Johnsgard 1965)
  • Honking calls develop at 6-8 months of age (Carboneras and Kirwan 2017)

Aggression among conspecifics

• Behaviors
  • Threat (Marchant and Higgins 1990)
    • Stare and walk toward opponent
  • Lunge (Davies 1963)
  • Chase (Davies 1963)
  • Claw (Davies 1963)
  • “Concert Calls” (Davies 1963)
    • Threat display
    • See Vocalizations
    • See Courtship
  • May rise into the air and beat each other with wings and strike with feet and bill (Davies 1963; Johnsgard 1965)
• Adults
  • Fighting maintains dominance hierarchy (Marchant and Higgins 1990)
  • More common while feeding (Davies 1963; Frith 1967)
    • Flocks occur at higher densities
  • Dominant female in a breeding group pecks subordinate female(s) (Marchant and Higgins 1990)
    • See Social Relationships
• Goslings
  • Compete for food provided by parents (Kear 1973)
  • Behaviors (Davies 1963)
    • Pecking
    • Concerting (see above)
    • Goslings grip each other’s bills
      • Attempt to wrestle opponent to the ground

Passive defense

• Raise neck when alarmed (Marchant and Higgins 1990)
  • Survey surroundings
  • Often accompanied by head shaking
    • Ritualized behavior indicating tendency to flee

Active defense

• When alarmed, cluster together and quickly walk away from potential danger (Davies 1963; Frith 1967)
  • May take flight, if very alarmed
  • Goslings group together when fearful
• Also see “Defense of Eggs” in Parental Care

Breeding

• Defend nest site from predators (Davies 1963) and neighboring breeding groups of Magpie Geese (Marchant and Higgins 1990)
• Territories not maintained after hatching (Marchant and Higgins 1990)
• Do not defend feeding territories, but compete for food (Marchant and Higgins 1990)

Social learning

• Ability to recognize predators may, in part, be learned from flock members (Davies 1962a)

Mutual preening

• Observed when taking over nest care duties for a breeding partner (Johnsgard 1961)

Indicator species

• Used in assessments of potential impacts of large-scale agriculture on natural systems (especially freshwater systems) (Bayliss and Ligtermoet 2017)

Relationship with humans

• Important species in bird-watching tourism (Steven et al. 2015)
• Human-wildlife conflict where rice is cultivated (Frith 1967)
  • Little impact on agriculture (Frith 1967)
  • Geese controlled using nets and limited permitted take (Delaney et al. 2009)

Feral pigs

• Feral pigs (Sus scrofa) are the major feral ungulate pest of Magpie Geese habitats in Northern Australia (Peter Bayliss, personal communication, 2018)
  • Populations in Kakadu region increased following reductions in water buffalo densities in the 1980s
    • See below
• Impacts (Whitehead 1998b; Bayliss et al. 2017; Pettit, Naiman, Warfe 2017
  • Pigs compete with Magpie Geese for critical food (E. dulchis corms)
  • Digging damages soil conditions

Feral water buffalo

(Peter Bayliss, personal communication, 2018, and as noted)

• Historical impacts
  • Water buffalo (Bubalus bubalis) were introduced to river areas of northern Australia in the early 1800s (e.g., Ens et al. 2016; Pettit, Naiman, Warfe 2017)
  • Numbers reduced by a large-scale, nationl eradication program in the 1980s (Bayliss and Yeomans 1990)
    • Substantial reductions in remote areas of northern Australia (Peter Bayliss, personal communication, 2018)
  • Where present, water buffalo damaged Magpie Geese nesting and dry season feeding habitats (Corbett et al. 1996)
    • Buffalo grazing and trampling changed plant growth and distribution patterns; grasses used for nesting also displaced by other grasses
  • Magpie Geese were most impacted in Kakadu region
    • Buffalo pet meat industry in Kakadu region substantially reduced buffalo populations
• Possible future impacts (Peter Bayliss, personal communication, 2018)
  • Numbers of water buffalo increasing on Arnhem Land Plateau (Northern Territory)
    • Appear to be migrating back onto floodplains
    • Could become a problem again, if not managed

Water birds

• Rarely interact with other waterfowl (Johnsgard 1965)
• Defend nest from other water birds that approach too closely (Kear 1973)

Walking and running

• Often move slowly and cautiously (Delacour 1954)
• Walk and run with ease (Marchant and Higgins 1990)

Flying

• In flight, has somewhat vulture- or stork-like appearance (Johnsgard 1978; Todd 1979, except as noted)
  • Rounded wings
  • Slow wing beat
    • About three times per second (Davies 1963)
• Lowers body slightly before takeoff (Frith 1967)
  • Necessary to get heavy body into the air
  • Capable of a near vertical takeoff from a standing start (Marchant and Higgins 1990)
    • May run into wind for added lift (Frith 1967)
• In flight (Marchant and Higgins 1990)
  • Do not glide, except prior to landing
  • Neck is extended
  • Often in V-formation
• Can fly 25-30 mph (40-48 kph) (Davies 1963)

Swimming

• Rarely swim (Johnsgard 1961; Frith 1967)
  • Swim fairly well (Johnsgard 1965)
• Float high in the water (Johnsgard 1961)
• Not known to dive (Johnsgard 1961; Johnsgard 1965)

Breeding groups fly between roosts and feeding areas each day.

Groups are attracted to larger groups on the ground or in flight.

Image credit: © Graham Winterflood via Flickr, Creative Commons License BY-SA 2.0. Some rights reserved.

Image location: Queensland, Australia