辨識
Peak-headed diving duck. Males have black breast, finely-barred gray back, whitish sides (often slightly dusty-looking), and yellow eye. Head appears black with a purplish or greenish sheen in good light. Females are brown overall with white patch at base of bill and yellow eye. Very similar to Greater Scaup; note Lesser’s peaked head shape with angle near the rear of crown, slimmer cheeks, less extensive white stripe on wing in flight, and smaller, narrower bill. Also similar to Ring-necked Duck, but Lesser Scaup has grayer back and whiter sides. Usually in flocks or pairs on a variety of wetland habitats, from small ponds to large lakes and bays. Slightly more likely to be seen on smaller bodies of water, especially fresh water, than Greater Scaup, but much overlap. Frequently in mixed flocks with other Aythya ducks. Widespread across North America, with more southerly range extent than Greater Scaup, regularly reaching northern South America.