Spur-winged Goose

The Spur-winged Goose, Plectropterus gambensis, is a striking waterbird endemic to Sub-Saharan Africa. It is a member of the Anatidae family, which encompasses geese and shelducks, but has evolved unique anatomical features that distinguish it from its relatives, placing it in its own subfamily, Plectropterinae. This species is one of the largest true waterfowl in Africa and is considered the world's largest goose by average weight, with males being notably larger than females.

Identification Tips

Adult Spur-winged Geese measure between 75 to 115 cm in length and weigh approximately 4 to 6.8 kg, with some individuals reaching up to 10 kg. They boast a wingspan ranging from 150 to 200 cm. The plumage is predominantly black with a white face and prominent white wing patches. Their long legs are tinged with pinkish red. The male is distinguishable by a larger red facial patch extending from the red bill and a knob at the base of the upper mandible. The subspecies P. g. niger, found south of the Zambezi River, has a smaller white belly patch and can appear almost entirely black from a distance.

Habitat

The Spur-winged Goose favors open grasslands adorned with lakes, seasonal pools, rivers, swamps, and river deltas. It typically inhabits large inland rivers and lakes, avoiding saline lakes and arid zones. It can be found at elevations up to 3,000 meters in eastern Africa.

Distribution

This species is widespread across Sub-Saharan Africa, with the subspecies P. g. gambensis and P. g. niger occupying different regions. P. g. niger is particularly prevalent south of the Zambezi River.

Behaviour

The Spur-winged Goose is a social bird, often found in small flocks of up to 50 individuals. It spends the middle part of the day resting by water and feeds by grazing on plant matter, occasionally supplementing its diet with small fish or insects. The species is known for its aggressive behavior towards other waterfowl during the breeding season, using the spur on its wings in conflicts.

Song & Calls

The Spur-winged Goose is generally a quiet species. Males may emit a soft bubbling 'cherwit' when taking flight or feeling alarmed. Both sexes may produce other inconspicuous calls during breeding displays or when alarmed.

Breeding

Breeding seasons vary across their range, with northern populations breeding from August to December, eastern Africa from January to June, and southern Africa from August to May. Nests are large and usually concealed in vegetation near water, but they may also use tree holes, cavities in rocks, or even the nests of other birds.

Similar Species

The Spur-winged Goose can be confused with other large waterfowl, but its unique size, coloration, and the red facial patch in males make it distinguishable.

Diet and Feeding

The diet is predominantly plant-based, including grasses, sedges, aquatic plants, grains, fruits, and tuberous crops. They may also eat small fish or insects.

Conservation status

The Spur-winged Goose is classified as Least Concern by the IUCN. The main threats include habitat destruction and unregulated hunting. A survey in western Africa estimated a population of 10,000 individuals, with many found in the Niger basin. The species is protected under the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA).