Editing Steller's eider (section)

== Behaviour and ecology ==
=== Diet ===
[[File:Steller's Eider (Polysticta stelleri) (13667593713).jpg|thumb|A mixed flock of Steller's eiders and [[Long-tailed duck|Long-tailed ducks]]|290x290px]]
Steller's eiders forage primarily near the shore by employing various techniques such as briefly diving and swimming underwater (to a maximum depth of 9m), wading and dabbling.<ref name=":2">{{Cite web|date=2014-11-13|title=Steller's Eider|url=https://www.audubon.org/field-guide/bird/stellers-eider|access-date=2021-11-10|website=Audubon|language=en}}</ref><ref name=":3">{{Cite web|last=Chukchi Sea Lease Sale|date=2006|title=Biological Evaluation of Spectacled Eider (Somateria fischeri), Steller's Eider (Polysticta stelleri), and Kittlitz's Murrelet (Brachyramphus brevirostris)|url=https://www.boem.gov/sites/default/files/uploadedFiles/BOEM/About_BOEM/BOEM_Regions/Alaska_Region/Environment/Environmental_Analysis/Biological%20Evaluation%20for%20LS193%20Sept%2017%202007%20-%20stand%20alone.pdf|access-date=November 10, 2021|website=Bureau of Ocean and Energy Management}}</ref> They feed by surface techniques more than other sea ducks and prefer relatively small prey.<ref name=":7"/> Studies have shown that Steller's eiders are specialists in catching highly mobile prey but may limit their diet to [[crustacean]]s even when higher energy sources, such as [[capelin]], become available.<ref name=":4">{{Cite journal|last1=Bustnes|first1=Jan Ove|last2=Systad|first2=Geir Helge|date=December 2001|title=Comparative Feeding Ecology of Steller's Eider and Long-Tailed Ducks in Winter|url=http://dx.doi.org/10.2307/1522072|journal=Waterbirds: The International Journal of Waterbird Biology|volume=24|issue=3|pages=407|doi=10.2307/1522072|jstor=1522072|issn=1524-4695|url-access=subscription}}</ref> This discrepancy in food preferences may be due to their inability to exploit deeper habitats.<ref name=":4" /> Steller's eiders also feed on [[Mollusca|mollusks]], [[echinoderm]]s, [[Polychaete|polychaete worms]], and [[mussel]]s during the winter.<ref name=":5" /> While in the tundra during the summer months, they feed on aquatic insects and plant material such as crowberries and pondweeds.<ref name=":2" />

=== Reproduction ===
According to [[Bird ringing|banding studies]], Steller's eiders can live up to 21 years and four months and reach sexual maturity at two years.<ref>{{Cite journal|last1=Flint|first1=Paul L.|last2=Petersen|first2=Margaret R.|last3=Dau|first3=Christian P.|last4=Hines|first4=James E.|last5=Nichols|first5=James D.|date=January 2000|title=Annual Survival and Site Fidelity of Steller's Eiders Molting along the Alaska Peninsula|url=http://dx.doi.org/10.2307/3802998|journal=The Journal of Wildlife Management|volume=64|issue=1|pages=261|doi=10.2307/3802998|jstor=3802998|bibcode=2000JWMan..64..261F |issn=0022-541X|url-access=subscription}}</ref> Males engage in [[Lek mating|leks]] on the wintering and breeding grounds, where groups of males attempt to win over an individual female with elaborate displays.<ref name=":0" /> Males court females in silence by displaying a consistent sequence of side-to-side head-shaking while swimming towards and away from their potential female partner.<ref name=":0" /> Steller's eiders tend to form breeding pairs during late-winter to early-spring instead of the fall like most waterfowl.<ref name=":3" /> Breeding pairs arrive at their nesting sites as early as the beginning of June.<ref>{{Cite journal|date=March 1955|title=Bent, Arthur Cleveland. Life Histories of North American Fowl: Ducks, Geese, and Swans. Volumes I and II. New York (1780 Broadway); Dover Publications, 312 P. and 392 P. $8.00 for both volumes|url=http://dx.doi.org/10.1002/sce.3730390278|journal=Science Education|volume=39|issue=2|pages=184|doi=10.1002/sce.3730390278|bibcode=1955SciEd..39R.184.|issn=0036-8326|url-access=subscription}}</ref>

Females establish their nests in marshy tundra close to permanent open water that has additional access to small ponds.<ref name=":5">{{Cite web|last=Sea Duck Joint Venture|date=July 2016|title=Species Status Summary and Information Needs Steller's Eider (Polysticta stelleri)|url=https://seaduckjv.org/wp-content/uploads/2014/08/STEI-status-summary-July-2016-FINAL.pdf|access-date=November 10, 2021}}</ref> They specifically select mounds or ridges dominated by mosses, lichens, and grasses.<ref name=":1" /> Their nest is shallow, lined with grasses, moss, lichens, and [[Down feather|down]] feathers plucked from the female's breast, who builds the nest without help from the male.<ref name=":2" /><ref name=":0" />

Females usually lay 1–8 olive to brownish-orange eggs per breeding cycle.<ref name=":1" /><ref name=":0" /> She then incubates the eggs alone for about 25 days.<ref name=":6">{{Cite journal|last1=Quakenbush|first1=Lori|last2=Suydam|first2=Robert|last3=Obritschkewitsch|first3=Tim|last4=Deering|first4=Michele|date=2004-01-01|title=Breeding Biology of Steller's Eiders (''Polysticta stelleri'') near Barrow, Alaska, 1991–99|journal=Arctic|volume=57|issue=2|doi=10.14430/arctic493|issn=1923-1245|doi-access=free}}</ref> The young are [[Precociality|precocial]] and hatch between late June and late July with their eyes open and sporting downy feathers.<ref name=":0" /> However, predators consume the majority of eggs before they are hatched.<ref name=":1" /><ref name=":6" /> The young go to the water shortly after hatching and immediately feed themselves, without relying on their mother for food.<ref name=":1" /> Regardless of their feeding independence, females will stay within 700m of their nest for up to 35 days post-hatch, while the young begin flying approximately 40 days after hatching.<ref name=":1" /><ref name=":6"/> It is not uncommon for one female to assume care of two or more sets of young from a different mother.<ref name=":2" />
{| class="wikitable"
|+
! colspan="2" |<small>Average Nest Dimensions<ref name=":0" /></small>
|-
|Diameter
|14.6 inches
|-
|Height
|7.7 inches
|-
|Cup Diameter
|5.7 inches
|-
|Cup Height
|3.7 inches
|}

=== Vocalization ===
Males make a low jumbled growling sound, while females make a discrete qua-haaa sound of a similar tone.<ref name=":0" /> Males have also been reported to produce a repetitive crackling sound when females go underwater.<ref>{{Citation|title=XC203462 Steller's Eider (Polysticta stelleri)|url=https://www.xeno-canto.org/203462|access-date=2021-11-10}}</ref> Notably, the males [[Courtship display|court]] the females in silence.<ref name=":0" /> During flight, their feathers produce a mechanical whistling sound.<ref name=":0" />

=== Molt ===
After breeding, Steller's eiders gather in high-density flocks to synchronously molt (replace all their feather at the same time) in Arctic lagoons in northwest Asia and along the Alaska peninsula.<ref name=":7">{{Cite journal|last=Petersen|first=Margaret R.|date=August 1981|title=Populations, Feeding Ecology and Molt of Steller's Eiders|url=http://dx.doi.org/10.2307/1367319|journal=The Condor|volume=83|issue=3|pages=256–262|doi=10.2307/1367319|jstor=1367319|bibcode=1981Condo..83..256P |issn=0010-5422|url-access=subscription}}</ref> They remain flightless for about three weeks, but the entire flight-feather molt lasts from July to October.<ref name=":7" />  Juveniles molt first, followed by adult males and adult females.<ref name=":7" />