KING EIDERS - ARCTIC ROYALTY

By Paul Dye 

IN THE WILD
The vast majority of King Eider ducklings begin their lives north of the arctic circle in Siberia, Canada and Alaska, with only sporadic nesting in Iceland, Greenland and Scandinavia.  Kings are believed to have the most extensive range of any eider species, and with the possible exception of Longtails (Oldsquaws) they live and breed further north than any other waterfowl.

 
King Eider male - breeding plumage (photo by Lynn Dye)

Usually widely scattered over the arctic tundra, nesting densities rarely exceed one pair per 25 acres unless forced to concentrate in loose colonies on predator free river islands by numerous arctic foxes.  Most select a nest site less than 30 miles from the coast and within a half mile of a body of water.  An average of 5 eggs is deposited into a shallow depression in the dry grassy tundra, and insulated by the dark gray down from the female.  The eggs are an olive-buff color, slightly smaller than Common Eider eggs, but slightly larger than those of Spectacled Eiders.  If the eggs escape predation by arctic foxes, ravens, gulls and local native people, they hatch in 22 to 24 days.  As with most arctic nesting species, breeding success is highly variable with productivity severely curtailed during years of adverse weather.

King Eider ducklings are initially reared on fresh water, but soon escorted to the seacoast by being led either downstream or overland from pond to pond.  Due to the usually wide dispersal of nests, brood merging is far less common than observed in common eiders.  Nevertheless, large crèches of over a hundred ducklings of varying ages have been observed on occasion, and may be attended by only a few females, and at times by no adults at all.  Growth rates are rapid and nesting and growth are often a race against time as inland waters in the high arctic are frequently ice free for as few as 60 days.  A researcher in the 1950?s reported that while on fresh water in summer the females and young feed primarily on midge larvae and aquatic vegetation.

Once the female Kings begin incubation, their mates leave the nesting grounds to begin the molt at traditional locations at sea often more than 1,500 miles distant.  As the males molt into eclipse plumage by late July their frontal knob becomes shrunken and dull in color.  Later in the season the females complete a similar migration, followed shortly by the young of the year.  King eiders usually migrate close to the coastline and have been observed crossing over peninsulas, commonly called eider passes by the hundreds of thousands.  Kings that nest west of Canada’s mid-Victoria Island migrate west across the Bering Sea to unknown sites in Siberia.  Those that nest east of mid-Victoria Island head east to the Disco Bay region off western Greenland where they are joined by others from western and northern Greenland.  During migration the flight of Kings is often often swifter and more maneuverable than the larger common eiders and they may travel in small groups that maintain no particular shape or high in long undulating strings or wedge formations.

At sea, adult Kings utilize superior diving skills to dive to 180 feet.  They obtain foods similar to common eiders, such as bivalve mollusks, crabs, and echinoderms (especially sand dollars and sea urchins).  Eelgrass (Zostera) is suspected of being one of the few plant foods of importance to King eiders.  

During their winter period at sea Kings are believed to find new mates and renew old pair bonds in preparation for the coming spring.  The males courtship displays consist of several linked stages such as wing flapping, upwards stretch and pushing, bathing and a unique vocalization not unlike the gobble of a turkey mixed with the giggle of a child.  This is usually followed by a “periscoping” like display of his head and neck colors. 

And colors there are in abundance; from the powder blue hood over his crown and nape to the bulbous orange knob that adorns his forehead and the base of his violet-red bill to the triangular, sail-like tertial feathers held aloft from his inner wings.  There are few if any other waterfowl that can match him for beauty and elegance. On the water, a male king eider shows more black color than any of the other eiders, with the rear half of his body appearing black except for a narrow white line where the wings insert in his flanks and a white patch on the sides of his rump. 

Male King Eiders weigh an average of 3.6 to 4 pounds while females weigh an average of 3.4 to 3.6 pounds.  Kings are also the only eiders in which the feathering extends far forward along the sides and top of the bill.  Females are usually more reddish than female common eiders and have a decumbent crest, which corresponds to the unique bluish feather area on the male.  In flight King Eiders are slightly smaller and less bulky than Common Eiders, and on the males in a flock the discontinuity of the white on their breasts and upper wing coverts caused by the black color of their backs is readily apparent. 

Along with Longtails (Oldsquaws), King Eiders are the most abundant of arctic waterfowl.  World-wide estimates range as high as 10 million, with 1.5 million of them nesting in Russia and between 1 and 2 million breeding in America.  Accurate counts are difficult due to the inaccessibility of most of their habitats. 

IN AN AVIARY
While they are beautiful in the wild, the males are spectacular when viewed close-up in a captive setting.  From their pastel blue heads, peach colored breasts and soft looking rich orange-yellow knobs to their sharp black and white body colors and their pointed back “sails” they are a joy to watch.  Although the females grunting call is not unlike other eider species, the “whinney-like” courtship call of the male is unique.  In a manner similar to some other eider species Kings courtship displays usually include a “periscope display”,  showing their facial colors to potential mates. 

With the possible exception of Stellers Eiders, Kings seem to be the most difficult eider subspecies to breed in a captive setting.  Since the 1990?s a couple of aviculturists in the US and a small number in Europe have had some, althougth limited, success.  Fortunate for the breeders in Europe, a small supply of wild-collected eggs were recently still available from sources in Russia, so inbreeding may not become a problem for sometime to come.

 Discussions between myself and a couple of other successful King Eider breeders revealed that we feel that the best breeding success seems to result from housing breeding age Kings in trios (1 male to 2 females) during the nesting season.  While eggs may still be obtained from housing 2 or more males with the females, there appears to be a negative effect on egg fertility. 

Like other more difficult to breed species, they simply do not initiate nesting if something about their enclosure or companions do not meet with their approval.  Courtship or copulatory behavior does not indicate a satisfied female, a condition that must exist before nesting will be attempted.  I personally believe it can be something as seemingly innocuous as the occasional passage of an unfamiliar dog or coyote, or aggressiveness exhibited by another of the aviary’s inhabitants. 

A friend in Scotland has had his King Eiders nest in tall grass near his pond, but that has not been the case in my experience.  Mine have always selected a covered nest structure, possibly to shield their nest from the occasional heavy rains in my area.  In one case two sibling females both nested under a plastic outdoor end table designed to be used with garden furniture.  Beneath this table I had installed a 5” high three-sided and open-topped wooden box, filled with 2” of sand, topped by 1” of hay or cedar shavings.  In all other cases mine have utilized one of my standard goose nest structures, so popular with my snows, emperors and brant.   These nest structures are approximately 30” wide by 30” high and 36” deep front-to-back, with a mostly open front.  Only the top and back are solid, as the sides are made of 1” by 4” treated lumber .  These boards are spaced on the sides in a way to provide some privacy and protection from other aggressive waterfowl while still allowing the nesting pair the ability to monitor their surroundings. Into these structures I place a discarded automobile tire to contain the nest material.  I then fill the center of the tire 2/3 full of sand and then 1/3 full of hay or cedar shavings.

          
Two King Eider nest sites - (left) under garden table , and (right) in dry pen corner

I never attempt to double clutch my Kings, as I've found them to be such close-setters that they rarely come off the nest to eat.  It’s obvious that they must, but it’s rarely observed.  As rare and difficult to replace as they are I don’t dare risk nesting burn-out by encouraging them to go through the stresses of incubation more than once a year.  It’s a strictly personal decision but one I would recommend to those who are sensitive to the well being of their eiders. I do candle the eggs about 2 weeks into incubation, so that I can retire nests that are infertile, and plan optimum brooder house space for those that look good and strong.  This is a very exciting time of the year! 

As the eggs approach hatch date I remove them from the nest to a reliable incubator or hatcher.  In the case of first-time nesting females I usually replace all but one of the eggs with a similar “dummy” egg, so that the new nester can experience the rewards of her hard work.  It’s hard to prove, but I suspect this helps to encourage repeat nesting in future years.  Again it’s just a personal decision by a dedicated “eider lover”.  I only leave the duckling with it’s mom for a few days because in a mixed flock setting such as mine I’ve found that the little one begins to weaken slightly after 4 or 5 days, probably due to competition with other species for food.  At this time it is moved in with its siblings in the brooder house, where they seem to teach it “the ropes” of brooder life. 

The King Eider hatchlings are dry brooded for 2 to 5 days until I’m satisfied that they are all eating the Mazuri Waterfowl Starter and are seeking out the heat lamp for heat.  They are then moved to a wet brooder with the same heat source and feed dish to reduce the stress of moving.  They are reared in the wet brooder until almost 1/3 grown with feathers just beginning to show on their sides.  At this point they are moved outdoors to my first-stage rearing ponds where they still have a heat lamp available for a day or two, until I'm satisfied that they’ve “hardened off”, or adapted to outdoor conditions.  At each of these stages it’s important to keep in mind that like most arctic species they soon demonstrate little need for the heat source and will stress if they are subjected to too much heat without the ability to escape. 

If you are going to pinion your young Kings to render them permanently flightless, it’s best done when they are 24 to 48 hours old.  At this age there is very little bleeding and almost no observable stress.  I no longer pinion all my King Eider ducklings as I try to encourage my friends and customers to more fully enjoy their antics and beauty in a flight aviary. 

Once my Kings outgrow the Mazuri Waterfowl Starter, when about half-grown, I gradually convert them to a diet of Mazuri Seaduck Diet, and then after a couple of weeks, supplement it with a small amount of Purina Hi-Pro Dog Meal thrown on the water at feeding time.  Most of the year I also provide small amounts of white millet and freeze-dried krill also thrown on the water as favored treats. These keep the eiders, as well as longtails and harlequins looking forward to my next visit and provide for  enjoyable interaction, as well as an opportunity to monitor their condition.  In addition, I believe the krill helps to avoid dietary deficiencies, such as for calcium,  that was a problem with my early eiders. 

The Kings have proven to be resilient when it comes to resisting most bacterial and viral infections, although I am currently apprehensive about west nile, as it appears to be heading our way.  I have taken early steps by installing more than 30 swallow and 8 bat nest boxes in and around the aviaries, to help control mosquitos.  I’ve also tried to monitor the development of a west nile vaccine by the CDC and AZA, but success seems to be slow in coming as of now.

I have lost an occasional eider of each species to aspergillosis.  A vaccine made by a state or private lab seems to be at least a partial success in building a level of resistance.  It’s made I’ve been told, by a standard method from spores removed from a bird that died of the disease on the premises.  The only treatment for aspergillosis that has shown any success once a bird exhibits early symptoms has been sporinox, but it must be prescribed by a veterinarian, and given to the stricken bird with fatty food. 

Their outstanding beauty, dynamic courtship including unusual vocalizations and tameness all contribute to the King Eider being absolutely one of the most enjoyable waterfowl to keep in an aviary setting.  They bring me constant pleasure. 

References:
Bellrose, Frank C.,  Ducks, Geese and Swans of North America,  Stackpole Books,
ISBN 0-8117-0535-8

Johnsgard, Paul A., Waterfowl Of North America, Indiana University Press,
ISBN 0-253-36360-8

Todd, Frank S.,  Natural History of The Waterfowl,  Ibis Publishing Co.,
ISBN 0-934797-11-0