home   about   search

biodiversity explorer

the web of life in southern Africa

Anas undulata (Yellowbilled duck)

Geelbekeend [Afrikaans]; Idada (generic term for duck) [Xhosa]; iDada (generic term for duck) [Zulu]; Siwoyo (generic term for duck) [Kwangali]; Letata (generic term for duck) [South Sotho]; Dada, Sekwe (both are generic names for duck or goose) [Shona]; Sekwa (generic term for duck or goose) [Tsonga]; Sehudi (generic term for duck) [Tswana]; Geelbekeend [Dutch]; Canard à bec jaune [French]; Gelbschnabelente [German]; Pato-de-bico-amarelo [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

Anas undulata (Yellowbilled duck)

Yellow-billed duck, Heldeberg Nature Reserve, Western Cape, South Africa. [photo Duncan Robertson ©].
Anas undulata (Yellowbilled duck)

Yellow-billed duck, Strandfontein Sewerage Works, Western Cape, South Africa. [photo Duncan Robertson ©].

The Yellow-billed duck is found mainly in South Africa, where it is very common. It lives in most types of wetlands, as long as they are still-bodied and not saline. The adults feed mainly feed on plants, while the juveniles eat mainly invertebrates. The female builds the nest, which is a shallow depression in the ground, lined with fine plant matter. It lays 2-10 eggs, which are incubated solely by the female, for 26-29 days. The chicks are cared for by their mother, and take their first flight at 68 days old. They become fully independent 6 weeks after fledging.

Records

Heaviest adult female to do
Heaviest adult male to do
Lightest adult female to do
Lightest adult male to do
Longest living 29 years 1 month
Longest distance travelled > 1000 km

Distribution and habitat

Found mainly in South Africa, where it is very common. It also occurs in patches of Botswana, Namibia and Zimbabwe, although it is hard to find in these areas. It generally prefers still waters of streams, lakes, swamps, pans, swamps, marshes and sewerage ponds. It avoids saline or highly acidic water and is largely absent from fast-flowing waters.

Distribution of Yellow-billed duck in southern Africa, based on statistical smoothing of the records from first SA Bird Atlas Project (© Animal Demography unit, University of Cape Town; smoothing by Birgit Erni and Francesca Little). Colours range from dark blue (most common) through to yellow (least common). See here for the latest distribution from the SABAP2.  

Movements

Nomadic, moving between different wetlands and vleis. It rarely travels long distances, although individuals have been recorded to move more than 1000 km.

Predators and parasites

Food

It feeds mainly on plants, supplemented with animals (which form approximately 17% of its diet). However the juveniles have a diet dominated by animals, eating more plants as they get older. The following food items have been recorded in its diet:

  • Plant matter
    • Potamogeton pectinatus (Sago pondweed)
    • Eleocharis (Sedge)
    • Lagorosiphon (Oxygen weed)
  • Invertebrates
    • insects
      • midge larvae (Chironomidae)
      • water beetle larvae (Dytiscidae)
      • Orthoptera (crickets and grasshoppers)
    • Bulinus (Snails)

Breeding

  • The Yellow-billed duck is a monogamous, solitary nester. It has a very complex courtship display, involving fighting, preening, synchronized swimming, acrobatic flight and strange calls. The pair bond is very short, breaking before the chicks have hatched.
  • The female builds the nest, which is a shallow depression in the ground, lined with fine grass or weeds. It is usually placed in dense cover, never more than 20 metres away from water.
  • Egg-laying season is year-round.
  • It lays 2-10 eggs at daily intervals.
  • Incubation is done solely by the female for 26-29 days. She will sometimes leave the nest for short periods, covering the eggs with a scrap of nest lining.
  • The chicks are closely cared for by their mother for their first three weeks of their lives. They usually have their first flight at 68 days, but they remain with their mother for 6 weeks after fledging, after which they become fully independent.

Threats

Not threatened, in fact has benefited from human disturbance. It is hunted by humans, but there is no evidence to suggest that this affects its numbers significantly.

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.