Plectropterus gambensis (Spur-winged goose) 

Wildemakou [Afrikaans]; Ihoye [Xhosa]; iHophe (also used for Redeyed and Cape turtle doves -check), iHoye [Zulu]; Esokwe [Kwangali]; Letsikhoi, Letsikhui [South Sotho]; Sekwagongwana, Sekwanyarhi [Tsonga]; Legôu (also applied to Egyptian goose), Letsikwe [Tswana]; Spoorwiekgans [Dutch]; Oie-armée de Gambie [French]; Sporengans [German]; Pato-ferrão [Portuguese]

Life > Eukaryotes > Opisthokonta > Metazoa (animals) > Bilateria > Deuterostomia > Chordata > Craniata > Vertebrata (vertebrates)  > Gnathostomata (jawed vertebrates) > Teleostomi (teleost fish) > Osteichthyes (bony fish) > Class: Sarcopterygii (lobe-finned fish) > Stegocephalia (terrestrial vertebrates) > Tetrapoda (four-legged vertebrates) > Reptiliomorpha > Amniota > Reptilia (reptiles) > Romeriida > Diapsida > Archosauromorpha > Archosauria > Dinosauria (dinosaurs) > Saurischia > Theropoda (bipedal predatory dinosaurs) > Coelurosauria > Maniraptora > Aves (birds) > Order: Anseriformes > Family: Anatidae

Spur-winged goose. [photo Callie de Wet ©]	Spur-winged goose, Table view, South Africa. [photo Trevor Hardaker ©]

The largest duck or goose in Africa, weighing up to 7.45 kg. Widely distributed in Sub-Saharan Africa and with broad habitat preferences. Eats mainly plant matter, either from in and around water bodies or on dry land (seedlings and grain from crop lands are a favourite, which make them unpopular with farmers) . However, they do eat insects (e.g. termite alates) and young are known to catch and eat small fish. 

Records

By far the largest and heaviest duck or goose species in Africa. The next heaviest is the Egyptian goose at a maximum weight of 3.01 kg. 

Distribution and habitat

Found through most of the Sub-Saharan region. Widespread in southern Africa but absent to sporadic in semi-arid and arid regions. Can be found on virtually any internal water body and also encountered in grassland, karoo and on crop fields. 

Predators and parasites

• Ectoparasites (parasites on the outside of the body)
  • Hexapoda (insects) > Malophaga (lice) > feather lice
    • Holomenopon tumidum
    • Acidoproctus taschenbergii
    • Anatoecus icterodes
    • Anaticola asymmetricus
    • Trinoton gambensis
  • Hexapoda (insects) > Diptera (flies) > Hippoboscidae
    • Ornithoctona laticornis
  • Arachnida (arachnids) > Acarina (mites and ticks)
    • nasal mites
      • Rhinonyssus rhinolethrum
    • feather mites
      • Bdellorhynchus psalidurus
    • ticks
      • Amblyomma variegatum
• Endoparasites (parasites inside the body)
  • schistosomes
    • Gigantobilharzia plectropteri
    • Trichobilharzia spinulata
    • Trichobilharzia - 3 other species
• Pathogens
  • Clostridium botulinum Type C: only one case reported - unlikely to be highly prevelant because of plant-dominated diet.

Food

• Water-based foraging:
  • plant matter constitutes the bulk of the diet:
    • Potamogeton pectinatus (Sago pondweed): eats the rhizomes, stolons, leaves
    • Potamogeton crispus (Wavy-leaved pondweed)
    • Typha latifolia (bulrush): eats the shoots
    • Phragmites australis (Common reed): eats the shoots
    • Juncellus laevigatus (sedge): eats the seeds
    • Alisma plantago (Water plantain)
    • Stigeoclonium (filamentous alga)
  • animal matter
    • young birds dive for small fish and eat them
• Land-based foraging:
  • plant matter constitutes the bulk of the diet
    • Seeds, leaves, corms of grass (Poaceae)
      • Urochloa panicoides (Signal grass)
      • Cynodon dactylon (Couch grass)
      • Eleusine indica (Goose grass)
      • Panicum repens (Couch panicum)
    • from cultivated fields
      • ripe kernels and seedlings of grain crops (not popular with the farmers)
        • maize
        • wheat
        • oats
        • barley
        • sorghum
        • lucerne
        • potatoes
        • sweet potatoes
        • peanuts
        • sunflower seeds
        • rice
  • animal matter
    • insects
      • termite alates
      • Hemiptera (bugs)
      • Coleoptera (beetles and their larvae)
      • caterpillars (larval stage of Lepidoptera)

Breeding

• Pair bond does not last long: male generally moves off once the young have hatched, but before this he devotes some attention to protecting the breeding territory.  

Spur-winged goose nest with eggs, Wakkerstroom, South Africa. [photo Warwick Tarboton ©]

• Nest is placed in a shallow scrape in the ground and consists of a bowl of grass, reed stems and other plant material collected by the female in the vicinity and lined with her down. The nest is usually placed in dense grass or reeds on an elevated piece of land near water (e.g.  an embankment, island, termite heap). However, also known to nest in Aardvark (Orycteropus afer) burrows (like South African Shelduck) or up to 16 m above the ground in tree bole or on the vacated large nest of a Hamerkop, Sociable weaver, Martial eagle or African fish-eagle. 
• Breeding season (laying dates). Any time of year
• The female lays 7-14 eggs and on clutch completion, incubates them for 30-31 days before they hatch. Clutches of up to 27 have been recorded but these are thought to be the result of laying by more than one female. The female leaves the nest to feed in the early morning and/or in the late afternoon, and while she is away from the nest, she leaves the eggs covered with down to protect them and to keep them warm. 
• Young leave the nest soon after hatching and are cared for only by the female. They have developed their flight feathers (i.e. they have fledged) by about 85 days old and are able to fly soon after (earliest record of first flight is 100 days). 

Threats

• Unpopular with grain farmers, but its negative effect on agricultural production is usually minimal. However this does expose it to being shot by farmers.
• Hunters like shooting them because of their large size. However, this has had a negligible effect on populations, except perhaps in Botswana. 
• Overall, the Spurwing goose has expanded its distribution and density because of the building of dams and increased food supply (crops). 

References

• Hockey PAR, Dean WRJ and Ryan PG (eds) 2005. Roberts - Birds of southern Africa, VIIth ed. The Trustees of the John Voelcker Bird Book Fund, Cape Town.