Overview
The Spectacled Eider (Somateria fischeri) is one of the world’s most spectacular and biologically fascinating sea ducks. Renowned for the theatrical, velvet-like ocular patches that give the species its common name, this northern waterfowl breeds exclusively along remote Arctic coastal tundras in Alaska and Siberia. For decades, the wintering grounds of the entire global population remained an absolute ornithological mystery, until satellite-tagged birds were discovered in the mid-1990s congregating by the hundreds of thousands within tiny openings in the dense sea ice of the central Bering Sea.
Biology and Physical Characteristics
Breeding males display an extraordinary aesthetic: a pale pistachio-green head adorned with enormous, velvety white circles around the eyes that are finely bordered with black, resembling oversized spectacles. A bright orange bill is shielded by a feathered forehead shield, while the back is creamy-white and the breast and belly are contrasting jet-black. Females exhibit cryptic warm-tawny plumage barred with dark crescents for nesting camouflage, yet retain distinctive pale spectacle goggles. As specialized diving ducks, they possess dense down plumage, salt glands, and muscular legs placed far back on the body for powerful underwater propulsion.
Behavior and Ecology
During the brief Arctic summer, pairs nest in shallow depressions on wet sedge tundra and small coastal islands. Once ducklings fledge, spectacled eiders transition to a fully marine life, molting their flight feathers offshore. In the dead of Arctic winter, virtually the entire world population gathers into massive, dense flocks packed inside polynyas—leads of open water kept ice-free by strong ocean currents and the birds’ continuous swimming. From these icy holes, they dive up to 60 meters (200 ft) into pitch-black waters to vacuum benthic clams and marine worms off the continental shelf floor.
Conservation and Human Impact
Between the 1970s and 1990s, the breeding population on Alaska’s Yukon-Kuskokwim Delta plunged by over 96 percent, prompting federal listing under the US Endangered Species Act. Heavy lead shot poisoning from historical waterfowl hunting, marine oil spills, and reductions in benthic clam beds were identified as primary threats. Banning lead ammunition on breeding grounds and establishing critical marine wintering habitats have slowed declines, though climate-driven shifts in Bering Sea benthic ecosystems and changing sea ice dynamics remain critical monitoring priorities.
Interesting Factoid
The entire world population of spectacled eiders winters together in dense openings within the frozen Bering Sea, diving in sub-zero darkness to the ocean floor to harvest clams!
Last updated: October 2026