- 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
- A. u. rueppelli
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, JF. 2010. The Clements Checklist of Birds of the World. 6th ed., with updates to December 2010. Ithaca: Cornell Univ. Press. ISBN 978-0801445019. Spreadsheet available at http://www.birds.cornell.edu/clementschecklist/Clements%206.5.xls/view
- BirdForum Opus contributors. (2021) Yellow-billed Duck. In: BirdForum, the forum for wild birds and birding. Retrieved 11 April 2021 from https://www.birdforum.net/wiki/Yellow-billed_Duck