Editing Surf scoter (section)

== Description ==
The Surf Scoter reaches sexual maturity after 3 years. The adult male is on average 1,050 g (2.31&nbsp;lb) and 48&nbsp;cm (19&nbsp;in) in length while the adult female averages about 900 g (2.0&nbsp;lb) and 44&nbsp;cm (17&nbsp;in) in length, making this the smallest species of scoter on average.<ref name="Johnsgard">{{cite book|last1=Johnsgard|first1=Paul A.|author-link=Paul Johnsgard|title=Waterfowl of North America|date=1975|publisher=Indiana University Press|location=New Haven (USA)|isbn=978-0-253-36360-2|pages=[https://archive.org/details/waterfowlofnorth0000john/page/432 432–438]|url-access=registration|url=https://archive.org/details/waterfowlofnorth0000john/page/432}}</ref> The surf scoter has a wingspan of 29.9–30.3 in (76–77&nbsp;cm).<ref>{{Cite web|title=Surf Scoter Identification, All About Birds, Cornell Lab of Ornithology|url=https://www.allaboutbirds.org/guide/Surf_Scoter/id|access-date=2020-09-26|website=www.allaboutbirds.org|language=en}}</ref>

The male is completely velvety black except for white patches on the forehead and the nape. It has a swollen bill, appearing orange at a distance but patterned with white, red and yellow, and a black spot near the base.
The female is browner than the male, with a fairly uniform plumage, slightly darker above than below. Indistinct paler patches are present on the cheeks below the eye and sometimes a whitish patch is on the nape, a unique trait among scoters. The bill is black with green or blue colorations
The juvenile has a plumage similar to the female, but mainly paler and browner, and the breast and belly are whitish.<ref name="Palmer">{{cite book|last1=Palmer|first1=R. S.|title=Handbook of North American Birds, Vol 3 (Waterfowl)|date=1976|publisher=Yale University Press|location=New Haven}}</ref>

The surf scoter is easily distinguishable from other scoters by the white patch on the head of the adult male and its unique bill pattern. Females and immatures have a bulkier bill with a squarish base and a more flattened head profile than other scoters. The black and the white-winged scoters are physically very similar to the surf scoter but in flight, the surf scoter is the only one with completely dark wings.<ref name="Palmer"/>

Like all sea ducks, the surf scoter becomes flightless during the simultaneous [[molt]] of its [[flight feathers]]. This vulnerable period happens usually in late July through early August and lasts for about four weeks. This wing molt is the start of a complete body or prebasic molt which is completed in the fall producing the next basic or breeding plumage. Before the prebasic molt, many duck species undergo a partial prealternate molt replacing the bright colors of the basic plumage of males by the duller [[Alternate plumage|alternate]] or [[eclipse plumage]] but the prealternate molt is believed to be limited or absent such that males appear similar in both basic and alternate plumage, but may have a browner belly and duller or "messier" appearance in summer.<ref>{{Cite book |last=Reeber |first=Sébastien |title=Waterfowl of North America, Europe, and Asia: An Identification Guide |publisher=Princeton University Press |year=2016 |isbn=978-0691162669}}</ref>

The plumage is a good indicator of the age for male surf scoters, but not for females. Second-year males are similar to adults but may have brownish feathers and/or lack the white forehead patch.<ref name="Iverson">{{cite journal|last1=Iverson|first1=Samuel A.|last2=Esler|first2=Daniel|last3=Boyd|first3=W. Sean|title=Plumage characteristics as an indicator of age class in the surf scoter|journal=Waterbirds|date=2003|volume=26|issue=1|pages=56–61|doi=10.1675/1524-4695(2003)026[0056:pcaaio]2.0.co;2|s2cid=12421202 }}</ref>

=== Vocalization ===
Surf scoters are generally silent and their few vocalizations are poorly known. During courtship display, males perform a gurgling call and an explosive ''puk-puk''. Females defend their young with a crowlike call.<ref name="Johnsgard"/> When alarmed, surf scoters will often make a sound like a "guk," somewhere between a "cluck" and a "tok," while rapidly surveying their environment or taking to flight en masse.