Common Eider

Fascinating facts about the Common Eider

• A female common eider will pluck the down feathers from her own breast — up to 500 grams worth — to line her nest and insulate her eggs from Arctic temperatures that plunge to -40°C. Once the ducklings hatch, she never replaces those feathers, spending the summer exposed and vulnerable. Eiderdown is so thermally efficient that humans still harvest it for the world's finest quilts and parkas, each premium duvet requiring the down from roughly 75 ducks.
• Common eiders can dive to 60 metres underwater to prise mussels and sea urchins from the seafloor using their tough, serrated bills — depths that would crush most ducks' lungs. They stay submerged for up to a minute, their heart rate dropping by 90 percent to conserve oxygen. This deep-diving lifestyle means they're trapped in ice-free waters year-round, making them climate sentinels; as Arctic sea ice vanishes, eider populations collapse because their feeding grounds freeze over or disappear entirely.
• Male eiders perform one of nature's most elaborate courtship displays: a 10-bird synchronised dance where they throw their heads back, arch their necks, and call in unison to impress females. The display is so demanding and so critical to mating that males will starve themselves during breeding season, losing up to 40 percent of their body weight before they ever pair with a female. A single unsuccessful season means no offspring — and no second chances if the window closes.
• Arctic Inuit and Norse peoples harvested eiderdown for over 1,000 years, and Iceland still operates licensed eider colonies where farmers protect nesting sites and hand-collect shed down. A single eider farm can produce 1 tonne of down annually. This ancient partnership means common eiders are one of the few wild birds that recognise humans as allies rather than predators — they'll nest metres from houses and allow people to walk past incubating eggs unafraid.
• In just 8 weeks, a common eider duckling grows from a 45-gram chick into a 1.5-kilogram juvenile capable of diving and feeding itself — one of the fastest growth rates among ducks. Mothers teach their ducklings which mollusks are safe to eat by repeatedly diving and surfacing, creating underwater apprenticeships that last through summer. But fewer than 20 percent of ducklings survive to fledging, making the Arctic's feast-or-famine seasons a brutal crucible where timing everything — ice melt, food blooms, predator cycles — means the difference between a thriving population and collapse.

At a glance

About the Common Eider

In the rugged, windswept landscapes of the northern hemisphere, the Common Eider glides effortlessly, its sleek, black-and-white feathers glistening like polished stone as it navigates the turbulent tides. With a gentle, rolling motion, it paddles through the waves, its webbed feet propelling it with a quiet strength, as if drawn by an unseen current to the hidden coves and rocky outcroppings that cradle its precious nests. As it moves, the Eider's soft, cooing calls weave a haunting melody, a siren's song that echoes across the wild, unforgiving beauty of its native shores.

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