- 18.5–25.2 in
- 42.3–74.1 oz
- Eider à tête grise, Eider remarquable (French)
- Eider real (Spanish)
- The King Eider forages on sea beds up to 25 meters (82 ft) deep.
- The female King Eider alone attends the nest. When an intruder is present, the female sits low on the nest with her head flattened on the ground. She sits tightly on the eggs and sometimes can be touched or picked up off of the nest.
- The female King Eider does not feed very often during the 22-24 day incubation period. One female did not leave her nest for seven days before being flushed by an arctic fox.
- The oldest recorded King Eider was a female and at least 22 years, 1 month old when she was recaptured and rereleased during banding operations in Nunavut.
Nests in various tundra habitats, generally in low marshy areas. Winters in marine environments near coastlines or on open water shallow enough to allow for foraging at the bottom.
Aquatic insect larvae, crustaceans, and plant matter in summer. In winter, feeds on a wide variety of marine animals, including mollusks, crustaceans, and echinoderms, as well as algae.
- Clutch Size
- 2–7 eggs
- Egg Description
- Olive or olive-buff.
- Condition at Hatching
- Covered in down and able to leave the nest soon after hatching.
A scrape on the ground, usually near water, lined with vegetation and down from the female.
During the breeding season, feeds by tipping up, probing, or diving, depending on water depth. In winter, most commonly dives to sea floor to take prey.
There is little information on King Eider population trends and numbers, though there may be some recent population declines, especially in western North America. King Eider is not on the 2014 State of the Birds Watch List.