Spectacled eider

Spend most of the year in marine waters, where they feed primarily on bottom-dwelling mollusks and crustaceans. 
In spring, breeding pairs move to nesting areas on wet coastal tundra and establish nests near shallow ponds or lakes. During the spring season they feed by dabbling in ponds and wetlands, eating aquatic insects, crustaceans, and vegetation. 
 

Seaducks are generally winter-hardy and sociable. They are preferably kept on a large area of clean, cold, deep water, at least some of which (preferably half the area) should be more than 60cm and preferably more than1m deep. As with other diving ducks, most species are relatively ungainly on land and ponds should have shallow sloping banks. Some cover along the pond edges will generally be appreciated. Preferred nesting sites vary greatly within this group, from open ground nesting to thick vegetation and tree holes.

Diets of grain, pellets fish and seafood may be used, also bread. These ducks generally need a higher-protein diet than most waterfowl species and high-protein pelleted diets specifically designed for seaducks are now available, although supplementation with fish may still be important particularly for breeding.

Feeding in troughs containing stones may avoid the development of overgrown bills. Provision of salt water may decrease the incidence of fungal and other infections.

Ducklings may be given high-protein starter crumbs and live food, and provided with access to deep water for swimming from an early age.

Eiders should be provided with clean, deep, cold water, with ice-free water available in winter, and may be best kept as flocks rather than as individual pairs. They will eat large quantities of fish if it is offered. They are prone to Foreign Body Ingestion while searching for grit, and are also susceptible to heat stress and to Aspergillosis.

Spectacled eiders have been kept in only small numbers and bred rarely in captivity. Open and close ground cover should be available for nesting, with egg laying mainly May to June.

The ideal relative humidity for incubating most waterfowl eggs is 55% (ground nesters) and 40% (cavity nesters). The temperature is usually 37.4°C. Set ventilation as recommended by the incubator manufacturer. Eggs must be turned, either automatically or by hand, a minimum of 4 times a day. As the duckling develops there is a loss of water from the egg and the air sac gets bigger. In normal development of an egg with a 24-25 days incubation, the air sac occupies about a third of it three days earlier. Cleanliness is vital and ideally eggs should be moved to a separate hatcher at this point, where the humidity should be increased to 65% and even higher once they have pipped internally.