A duck distributed in eastern and southern Africa. It uses shallow freshwater wetlands with vegetation; the male’s bill becomes redder during breeding, according to the regional account.
Adults are brown above and buff below, with mottled or barred feathers. The male’s bill is brighter red during breeding; females differ subtly around the forehead and bill ridge. Juveniles are duller and greyer than adults.
In South Africa’s Wilderness Lakes Complex, waterbirds were counted in summer and winter twice a year from 1992 to 2019. Red-billed Duck was recorded more often in winter across the complex. Long records from six waterbodies also showed that local changes differed from lake to lake.
Summer numbers rose on Rondevlei over the survey period. On the Swartvlei system, counts rose into the 2000s and then fell in the 2010s. The twice-yearly surveys captured both seasonal abundance and changes that differed among waterbodies.
Four observers counted waterbirds from a boat along repeated routes. Surveys took place in calm weather; when wind reduced counting accuracy, a survey was stopped and resumed another day.
An extinction-risk assessment has not been added yet.
The Wilderness Lakes record showed summer increases on Rondevlei alongside declines on the Swartvlei system in the 2010s. Keeping waterbody-level records preserved these contrasting local changes.