May. 29, 2012

My Sister Species: The Common Eider

by Coastal Studies for Girls

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by Mel, 10th Grade, Coastal Studies for Girls
Here at Coastal Studies for Girls, each girl is assigned a sister species. These species may be ones we encounter throughout the semester, or else are other marine species that live in Maine. We study our assigned sister species and also learn about each other’s species to get a better understanding of marine life. Our goal is to really appreciate these wonderful animals that live just along the coast.
My sister species is the Common Eider, which at first I did not even know is a sea duck. I am very excited to learn about this animal, and I also feel that I am lucky because I am able to see it almost every day at the shore,  flying just above the water, or floating on the surface.
The Common Eider, or Somateria mollisima (which is the Latin name) is a sizable sea duck that is found in the Northern Hemisphere. It is actually the largest duck in the Northern Hemisphere, with the average length of males 24 inches and the female average length 22.5 inches.  Males, on average, weigh 4.3 pounds, while females weigh 3.3 pounds on average. The Common Eider lives near the oceans, and spends winters offshore close to the fish-filled shores. It nests on the ground, near water, and its nest is padded with down from the mother and with vegetation. Females usually lay between three and five eggs.
Watching the Eiders, I have admired how they are able to dive below the surface of the water to capture their food thanks to their protective coat. The Common Eider eats mollusks, crustaceans, and even sea urchins!
While the female is brown and grey with a little yellow color, the male is more colorful. Males are black, white, and have green cheeks to attract the females. Common Eiders are distinct in the shape of their bill, which is wedge-shaped. In the 1800s, the population of Common Eiders declined greatly because of hunting. Common Eiders were very popular for their eiderdown, which is known to be the warmest feathers used in items such as quilts.
Another aspect of the Common Eider's biology that I find interesting is that Common Eiders are colonial breeders, and often return to breed to the same island where they were born. This leads to many related ducks on the same island and related ducks breeding with each other.
The Common Eider is a very interesting species, with a unique physical appearance and social behavior. I am so thrilled to learn more about it through the semester.
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