- Anas undulata
- Grey body
- Darker head
- Bright yellow bill
- Wings: white below with white-bordered green speculum (blue in the northern race)
Sexes similar. Juveniles slightly duller than adults
Western Africa: Mali, Cameroon, Democratic Republic of Congo and Angola
Eastern Africa: Sudan, Ethiopia, Djibouti, Kenya, Uganda, Rwanda, Burundi, Tanzania, Zambia, Mozambique and Malawi
Southern Africa: Namibia, Botswana, Zimbabwe, South Africa, KwaZulu-Natal, Lesotho and Swaziland.
Anas undulata has two subspecies:
- A. u. undulata
locally from Kenya and Uganda to Angola and South Africa; also local in eastern Nigeria and central Cameroon (but subspecies of this disjunct population not certain)
- A. u. ruppelli
Freshwater in fairly open country.
The diet includes plant food for which it dabbles mainly in the evening or at night.
It nests on the ground in dense vegetation near water. The clutch consists of 6-12 eggs.
- Clements, J. F., T. S. Schulenberg, M. J. Iliff, D. Roberson, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2017. The eBird/Clements checklist of birds of the world: v2017, with updates to August 2017. Downloaded from http://www.birds.cornell.edu/clementschecklist/download/
- BirdForum Opus contributors. (2021) Yellow-billed Duck. In: BirdForum, the forum for wild birds and birding. Retrieved 25 June 2021 from https://www.birdforum.net/wiki/Yellow-billed_Duck