The ring-necked duck (Aythya collaris) is a diving duck from North America commonly found in freshwater ponds and lakes. The scientific name is derived from Greek aithuia, an unidentified seabird mentioned by authors including Hesychius and Aristotle, and Latin collaris, 'of the neck' from collum, 'neck'. 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'. (Source: Wikipedia.org, CC BY-SA)