The ring-necked duck (Aythya collaris) is a diving duck from North America commonly found in freshwater ponds and lakes.
The adult male is similar in color pattern to the Eurasian tufted duck, its relative. Males are a little bit bigger than the female. It has two white rings surrounding its gray bill, a shiny black angular head, black back, white line on the wings, a white breast and yellow eyes. The adult female has a grayish brown angular head and body with a dark brown back, a dark bill with a more subtle light band than the male, grayish-blue feet and brown eyes with white rings surrounding them. Females also make a noise like trrr. The cinnamon neck ring is usually difficult to observe, which is why the bird is sometimes referred to as a "ringbill".