About Melanitta stejnegeri (Ridgway, 1887)
This section describes key distinguishing characteristics between Stejneger's scoter (Melanitta stejnegeri) and the white-winged scoter. Male white-winged scoters have browner flanks, most of their bill is dark yellow, and they have a shorter bill knob, a trait that brings them closer to the velvet scoter. By contrast, male Stejneger's scoters have a very tall knob at the base of a mostly orange-yellow bill. While males of the two species are overall quite similar, they can most reliably be told apart by head shape: white-winged scoters have a "two-stepped" profile between the bill and head, while Stejneger's scoters have a long "Roman nose" profile similar to that of a common eider. Additionally, the feathering along the base of the upper mandible forms a right angle in white-winged scoters, and an acute angle in Stejneger's scoters. Stejneger's scoter breeds in the far north of Asia, east of the Yenisey Basin. It winters in more southerly temperate zones of Asia, reaching as far south as China. The species forms large, tightly packed flocks on suitable coastal waters, and the flock tends to take off together. Though previously considered rare in North America, Stejneger's scoter may now be a regular visitor and possible breeder in Western Alaska, with recorded sightings in Nome, Saint Paul Island, and Gambell. One individual was observed in Helena Valley, Montana, between April and May 2015; this is the only confirmed North American occurrence of the species south of Alaska. A scoter seen in Monterey Bay, California, on January 15, 2014, showed characteristics that appeared consistent with Stejneger's scoter, but the record was not accepted by the relevant committee due to poor image quality. Stejneger's scoter is also a rare vagrant to Europe, and has been recorded from France, Finland, Poland, Iceland, Ireland, Norway, Scotland, and Sweden.
