Dendrocygna viduata (White-faced duck)

Dendrocygna viduata (White-faced duck)

Nonnetjie-eend [Afrikaans]; Idada (generic term for duck) [Xhosa]; iVevenyane [Zulu]; Ehilili [Kwangali]; Letata (generic term for duck) [South Sotho]; Dada, Sekwe (both are generic names for duck or goose) [Shona]; Lidada lemfula [Swazi]; Xiyahkokeni [Tsonga]; Sehudi (generic term for duck) [Tswana]; Witwangfluiteend [Dutch]; Dendrocygne veuf [French]; Witwenente [German]; Pato-assobiador-de-faces-brancas [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: Dendrocygnidae


White-faced duck fighting. [photo Callie de Wet ©]

White-faced duck, Rooiwal Sewage Works, South Africa. [photo Trevor Hardaker ©]	White-faced duck. [photo Callie de Wet ©]

This long-necked, dark brown duck with a white face and greyish-black bill has a wide distribution ranging from tropical America to Africa, Madagascar and the Comoro Islands. It is found mainly on inland waters in savanna and grassland regions, and in southern Africa is considered one of the most common ducks in these regions. It feeds both in the water (mainly on aquatic vegetation and seeds), and on land (mainly on grass seeds, including seeds from cultivated crops such as maize and sorghum). Small amounts of invertebrates are also eaten (molluscs and insects).

Distribution and habitat

Widespread: found in tropical America, sub-Saharan Africa, Madagascar and the Comoro Islands. Within sub-Saharan Africa, found in most regions except dense rainforest and arid areas. In southern Africa, it is found mainly in the Free State, North-West Province, Gauteng, Limpopo, Mpumalanga, KwaZulu-Natal, Swaziland, Mozambique, Zimbabwe, and south-western and northern Botswana. Found mainly on inland waters in savanna and grassland regions.

Distribution of White-faced 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.

Predators and parasites

Predators
- Haliaeetus vocifer (African fish-eagle)
Parasites
- pathogens
  - Clostridium botulinum Type C (avian botulism).
- ectoparasites
  - Phthiraptera (lice)
    - Holomenopon dendrocygni
    - Acidoproctus rostratus
    - Trinoton aculeatum
  - Acarina (mites)
    - Speleognathus womersleyi
  - Hirudinea (leeches)
    - Theromyzon cooperi: known to cause paralysis and death.

Food

Mainly plant matter (> 99% of diet)
- When feeding in the water eats:
  - young shoots of:
    - Potamogeton crispus (Pondweed)
  - leaves and stems of:
    - Najas horrida (Saw-weed)
  - seeds of the following aquatic plants:
    - Scirpus
    - Nymphaea (water lily)
    - Persicaria lapathifolia
    - Heliotropium indicum (String of stars) nutlets
  - tubers of:
    - Nymphaea (water lily)
  - algae:
    - Chara
- When feeding on land eats:
  - seeds/fruits of:
    - Zea mays (Maize)
    - Echinochloa pyramidalis (Antelope grass)
    - Eriochloa (Harpoon grass)
    - Leersia (swamp cut grass)
    - Panicum coloratum (White buffalo grass)
    - Panicum schinzii (Land grass)
    - Dactyloctenium aegyptium (Crowfoot)
    - Paspalum scorbiculatum (Creeping paspalum)
    - Dichrostachys cinerea (Sickle bush)
    - Persicaria serrulata (knotweed species)
    - Persicaria lapathifolia (Spotted knotweed)
    - Polygonum aviculare (knotweed species)
    - Sesamum triphylum (Sesame)
    - Hibiscus (hibiscus)
    - Atriplex (salt bush)
    - Ambrosia artemisifolia (Ragweed)
    - Ceratophyllum demersum
    - Sorghum (sorghum)
    - Amaranthus (pigweed)
    - Sida rhombifolia (Spiderleg)
Small amount of animal food eaten (< 1%) although in half-grown ducklings up to 7% animal material has been recorded in their diet. Recorded animals eaten include:
- molluscs
  - Melanoides tuberculata
  - Gastropoda
    - unidentified species
    - pulmonate snail (Thiaridae)
  - Pelecypoda
  - Concostraca
- insects
  - Diptera (flies)
  - Hemiptera (bugs)
  - Coleoptera (beetles)
  - other

Breeding

Nest consists of a scrape in the ground, lined with grass and other vegetable matter, and hidden among long grass, sedges or other vegetation. Nest is usually situated near the water's edge but can be up to 3 km away!
Egg-laying season is mainly in spring, summer and autumn (September to May), peaking in summer.


White-faced duck nest with eggs, Sericea farm, South Africa. [photo Warwick Tarboton ©]

The female lays 4-13 eggs (clutches of up to 16 eggs probably the result of more than one female laying), one egg being laid per day. Incubation probably starts after the clutch has been completed, lasts 26-30 days, and is undertaken by both sexes (but mainly the male).
Young are diving for food by 14 days, are able to fly by 63 days, and have adult plumage by about 180 days. The parents accompany the young until even after they have started flying. They are especially protective of the young in their early development and keep them well hidden and attract predators away from the young by using the broken-wing act.

Threats

Not threatened and in fact its distribution and density has increased as a result of the creation of artificial water bodies (e.g. farm dams) and the growing of grain crops, which they feed on.

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.