Thalassornis leuconotus - Dendrocygne à dos blanc
- Size: 43 cm
- Wingspan: -
- Weight: 625 à 790 g
Due to a certain resemblance with shovelers, the White-backed Duck was initially classified in the Oxyurinae. Today, it is considered more as a Dendrocygninae, the only representative of its genus. Hard to be confused with another duck, it could be mistaken with a grebe due to its particular colors. There is no sexual dimorphism even though males tend to be slightly bigger than females. The face is black-brown up to the eyes which stand out badly. Two white spots below the lores contrast strongly with the dark face and black-brown beak. This last one is more or less spotted with yellow and presents a strong lobe. The neck and sides of the head are chamois, the latter very speckled with black-brown. Dark and bristled feathers on the back of the crown and descending on the neck in a dark line occasionally give the bird a crested aspect. The rest of the body is covered with a plumage showing an able mixture of black-brown and beige-chamois which makes the bird very cryptic in a context of aquatic vegetation. A largely white back appears when the bird is in flight or when it splashes. The tail is extremely short. The legs are gray-greenish. The juvenile is similar to the adult but more dull. The white spots on both sides of the beak are also less visible. The insularis subspecies, smaller than the nominate one, reproduces itself in Madagascar. Its general aspect is darker.
Subspecific information 2 subspecies
- Thalassornis leuconotus leuconotus (e Cameroon to s Ethiopia and South Africa)
- Thalassornis leuconotus insularis (Madagascar)
Voice song and cries
The White-backed Duck prefers fresh water. It can therefore be found on lakes, lagoons, marshes and wetlands as well as on flooded meadows forming wide pools. It is also not unusual to observe it on shallow rivers as long as there is enough depth and an abundant floating vegetation such as water lilies. In Madagascar, it prefers forest lakes up to 1300 metres in altitude. In Uganda it has been seen up to 1800 metres and even up to 3000 metres in Kenya.
Behaviour character trait
The White-backed Duck is a mainly sedentary bird. However, it is known to move during the rainy season to take advantage of newly formed shallow waters, as well as during the post-nuptial period.
The White-backed Duck is rarely seen in flight. Its silhouette in flight, with its wide and short wings and its robust legs sticking out from its rudimentary tail, is striking. It usually only flies for short distances and at low height.
The White-backed Duck feeds exclusively underwater, its beak being perfectly adapted. It is mainly vegetarian and its diet consists of leaves and seeds of aquatic plants such as water lilies. The juvenile mostly searches for aquatic insect larvae and other small invertebrates.
The breeding season varies depending on the geographical location and can happen at any time of the year.
The White-backed Duck has a wide distribution across Sub-Saharan Africa, but its presence is mainly concentrated in a large swath of the continent extending from the Sudan and Ethiopia to the south of the Cape and Madagascar. Elsewhere it is found sporadically along a narrow band extending from Senegal to the south of Chad, passing through Mali and northern Nigeria. It avoids equatorial forests. Despite its wide distribution, the species is never abundant. The species is renowned for its sedentary behaviour, however, local and seasonal nocturnal movements do occur, though they are poorly understood.
Threats - protection
IUCN conservation status
in the Wild
There is little information about the population of White-backed Duck. It is considered non-threatened but there are recent indications of a decline. It is not hunted since its flesh is not considered appetizing. The subspecies of Madagascar may be more vulnerable, but again there is no recent information on its status. Its disappearance from some areas where tilapia has been introduced has been noted. This vegetarian fish, the most consumed in the world, destroys aquatic vegetation necessary for the White-backed Duck wherever it lives. Agricultural development and the proliferation of water hyacinth can greatly reduce its habitat. Finally, there is a high mortality from fishing nets, such as in Lake Naivasha, Kenya. The population levels would be 10,000 to 25,000 birds for Africa and 2,500 to 5,000 birds for Madagascar.
Sources of information
- IOC World Bird List (v13.2), Gill, F and D Donsker (Eds). 2023.
- BirdLife International, BirdLife International
- HBW Alive,
- Birds of Southern Africa, Tony Roocroft
- The Birds of Africa Vol VIII : The Malagasy Region, Safford R. et Hawkins F.
Translation by AI Oiseaux.net
published: 28-01-2017 - Updated: 08-02-2017
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