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16 August 2010 @ 08:49 pm
Nova Scotia, Day 6 - Common Eider Close-up  
After I left the beach I stopped to check out the harbour one last time to see how high the tide had risen. I was surprised to see one of the Common Eiders swimming right in the harbour, just paddling along and occasionally diving for food. This was the closest I'd ever been to one of these beautiful sea ducks, and I was thrilled with the excellent views and the chance to finally take some decent photos of this species.

The eider seemed a bit skittish when he realized I was watching him, and began swimming toward the middle of the harbour; so I was careful to photograph him while standing just out of view next to a pile of crates or crouched down behind the guardrail. Then a second eider came along, this one much darker, giving me double the opportunity to observe and photograph these ducks!

Common Eider

Both of the eiders were males; females are brown with a fine striped pattern which helps to camouflage them during the nesting season when they spend several weeks on land. This individual appears to be a moulting adult male, as remnants of the white cheek and back are still visible.

The largest duck in the northern hemisphere, the Common Eider is the sea duck most closely associated with marine habitat. It lives in arctic and subarctic coastal areas, where it frequents headlands, offshore islands and shoals, particularly those with rocky shores. In the winter, eiders rarely leave the water, and many populations remain as far north as possible where open water exists.

The second male was much darker. Males begin moulting in June and July and may travel up to several hundred kilometres from their breeding ground to find a place protected from weather and predators while they moult. The old, worn feathers are entirely replaced, and for three to four weeks the eiders are unable to fly. By mid-September, they have lost their crisp black and white breeding plumage, becoming dark brown to black with a pale brown stripe through the eye. The males are then able to fly again and prepare to migrate to their wintering grounds.

This species often nests in colonies of 10,000 or more individuals, and young Common Eiders receive care and protection from not only their mothers, but also nonbreeding females known as “aunts”. These aunts gather around nests containing young hatchlings to protect the nest from predators. When the ducklings are ready to leave the nest, the aunts will accompany the ducklings to the water with their mother.

Multiple broods, especially those that have been attacked by predators, will often come together to form "crèches" containing a few to over 150 ducklings. Once formed, a crèche tends to stay together while the young are being reared, although some of the aunts attending it may leave.

Common Eiders, like other sea ducks such as Long-tailed Ducks and scoters, do not enjoy high reproductive success. The eiders have only one brood each year, and each female usually lays only four or five eggs. Of these, only 50 to 70 percent of the eggs hatch successfully. The young are able to fly after 60 days, but few survive that long; many are lost to predators, exposure, or starvation in their first week of life. In good years, one duckling per adult pair may live long enough to take part in its first fall migration.

This species' low breeding success is compensated by high adult survival rates. Adults are often long-­lived, with a life span of up to 20 years, and estimated annual survival rates vary from 80 to 95 percent. In contrast, most other duck species raise more chicks to adulthood but lose 40 to 50 percent of adults each year.

Eiders are diurnal and feed by diving from 3 to 20 m to the bottom of the ocean where they consume prey items such as mussels, clams, scallops, sea urchins, starfish, and crabs. These food items are swallowed whole and crushed in the large gizzard so they can be digested.

It was a fantastic experience to view these ducks right in the harbour. As they were the only Nova Scotia specialty that I saw, I was thrilled to get such wonderful close-ups of these beautiful, large ducks!

Soul Diasporasoul_diaspora on September 20th, 2010 04:19 am (UTC)
Eiders are gorgeous ducks--exciting to see one up close! I've seen females up close (with young) in the wild, at Gaspe, but so far the only place I've gotten a good look at a male is at the Montreal Biodome. They have one in the Saint-Lawrence Marine ecosystem.
Gillian: Purple Columbinegillianm on September 22nd, 2010 12:01 pm (UTC)
I saw some females on my trip to Nova Scotia, though not as close. And I'd love to see a male in his gorgeous breeding plumage!