What the duck? 7 things you don’t know about the common eider

Male Common Eider. Photo by Greg Schechter /CC by 2.0

Call them common all you want but common eiders are really special birds. They spend much of their life sturdily bobbing along in frigid and turbulent oceans of the far north, and it’s because of that, many people don’t know much about them. But we’re here to change that with a few fun facts about these marvelous sea ducks.

Common Eiders? More like rad eiders in flight by Melissa Gabrielson/USFWS

1. Their scientific name means “softest down body”.

Photos: Left: common eider eggs by Danielle Brigida/USFWS || Right: Common eider ducklings and nest by USFWS

Somateria mollissima is the common eider’s scientific name. Somateria comes from Greek meaning “down body” and mollissima is Latin for “softest”.

While their scientific name doesn’t exactly roll off the tongue, it hints at the important role their down has played at keeping even us humans warm. We have documented proof that we’ve been using eider down since around the 7th century — think about that! And even today, people still collect, clean, and use eider down after the ducklings leave the nest.

2. They swallow their food whole

Eiders, especially the common eider, can dive quite deep, they’ve been documented diving up to 65 feet! This is where they catch their meals which often consist of mollusks, sea stars, crabs and other invertebrates. How do they eat them? Swallow them whole - no big deal, if you’re an eider.

3. They’re our largest duck

Their weight helps them dive, but takeoffs aren’t very smooth. Photo: Danielle Brigida/USFWS

Weighing up to six pounds actually helps when you have to dive deep for your food. Common eiders are considered the largest duck in the Northern Hemisphere. While they’re agile divers, their attempts to take off aren’t as seamless, but maybe they’re just trying to make us feel better for being good at so many other things.

4. Females don’t eat while incubating their eggs

Just powering through. Female common eider. Photo by USFWS.

Female common eiders hunker down and brave wind, cold, and hunger to see that their eggs hatch, spending over 99% of their time on the nest while they’re incubating. They’ll leave to take a drink every 2–5 days, but they don’t feed during the whole incubation period which is often around 25 or 26 days!

5. Males have an unusual green in their feathers

From afar the male common eider looks great too, but noticing their unique and beautiful ghostly green color on the upper neck can be hard to do from far away. Here’s a close-up of the male common eider’s green feathers.

Green feathers on male common eider. Photo by Pepper Trail/USFWS.

6. Common eiders form impressive crèches

Similar to duck daycare, but called a crèche, sometimes one or more female eiders have lots of ducklings in their care. Common eider crèches have been documented at having over 100 babies to one female! The chicks are very vulnerable at this stage but crèches have their advantages.

Common eider crèche by USFWS.

7. They Protect Their Eggs with Poo

When female eiders get spooked or are flushed off their nest, they’ll defecate on their eggs as they fly off. They are one of several species that do this, and while the reason isn’t exactly clear, there are thoughts that they’re either attempting to protect their eggs from predators or they’re pooping to make themselves more maneuverable as they escape.

Bonus Fact: There’s an Arctic Refuge Eider Project

For reasons we want to investigate, the Pacific common eider population has declined by 50–90% between the 1950s and 90s and has since stabilized at these reduced numbers.

What We Don’t Know… (but doing research to find out)

During a climate change vulnerability assessment, common eiders were reported to be the highest-risk seabird breeding on the North Slope of Alaska. Common eiders are vital subsistence species, contributing to food security in many communities and are therefore an essential component of both social and ecological coastal resilience. Our lack of information about population demographics limits our ability to understand the causes of the decline and propose actions that could benefit their recovery and management. So since 2014, a collaboration with non-profit, university, state, and federal partners, Arctic National Wildlife Refuge has been working on a Common Eider Research Project. This project has been studying common eider nesting behavior and continues to contribute to our understanding of this important sea duck.

By Danielle Brigida, National Social Media Manager
U.S. Fish and Wildlife Service