Yellow-billed duck

Anas undulata

Geelbekeend / Gelbschnabelente / Canard à bec jaune

The yellow-billed duck is a 51–58 cm long dabbling duck which is an abundant resident breeder in southern and eastern Africa.

This duck is not migratory, but will wander in the dry season to find suitable waters. It is highly gregarious outside the breeding season and forms large flocks.

These are mallard-sized mainly grey ducks with a darker head and bright yellow bill. The wings are whitish below, and from above show a white-bordered green speculum. Sexes are similar, and juveniles are slightly duller than adults. The north-eastern race is darker and has a brighter bill and blue speculum.

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern (IUCN, 2012).

Pollution is a threat that still needs to be controlled within the species's range to keep the current population stable (Kear 2005b). Hybridisation of the species with the Northern Mallard Anas platyrhynchos represents a threat to the integrity of the species (Hockey, et al. 2005, Kear 2005b, Owen, et al. 2006) because the two species hybridise easily and produce fertile progeny (Owen, et al. 2006). Northern Mallard Anas platyrhynchos was introduced both deliberately and accidentally into the Cape Provinces of South Africa and has since become naturalised (Owen, et al. 2006). Other exotic ducks may associate with the species (e.g. Laysan Teal at Gauteng Province) and these species pose a further potential threat (Owen, et al. 2006). The species is also susceptible to avian botulism, so may be threatened by future outbreaks of the disease (Blaker 1967). The species is hunted (Dean and Skead 1989, Little, et al. 1995, Kear 2005b), and although there is no current evidence that such activities pose a threat to the species (Dean and Skead 1989), hunting levels may still need to be controlled in order to maintain current population levels (Kear 2005b). The species is also traded at traditional medicine markets in Nigeria (Nikolaus 2001).

More information: http://www.iucnredlist.org/details/22680221/0

Above: adult Yellow-billed duck

Above: adult Yellow-billed duck

Above: adult Yellow-billed duck

Above: adult Yellow-billed duck