Common Eider

The Common Eider is New Hampshire’s only breeding “sea duck” (the group that includes all the species that regularly occur on the open ocean). They frequent rocky shorelines along the coast and at the Isles of Shoals, where they can be found year-round. As far as we know, nesting occurs only on the Isles of Shoals, and begins in April with courtship and egg-laying. Eider nests are comprised almost entirely of down feathers that the female preens from her belly, and these are what were traditionally harvested for down insulation (after substantial cleaning!). The chicks hatch about a month later and immediately take to the water. But while we’re used to seeing ducklings bobbing along behind their mother in the local pond, eiders have a very different experience, with surf crashing against the rocks of their island home.

Once eider chicks are in the water, they tend to gather into multi-family groups called “crèches.” These average 20-30 ducklings, although groups over 100 have been recorded, and chick survival is highest when there are 2-3 females. Crèches sometimes travel considerable distances from the nesting colony (up to 50 miles!) and are often seen along the New Hampshire coast as early as late May. To the best of our knowledge there are no nesting eiders in the state other than those at the Isles of Shoals, meaning that those tiny chicks bobbing in the surf swam the 7-8 miles separating the Shoals from the mainland.

As was the case with many other waterfowl, eider populations were severely reduced (in this case via egg and feather harvesting) in the 1800s, and the species was almost extirpated from the United States. A long recovery finally led to the species recolonizing New Hampshire in the 1970s, and now eiders nest as far south as the western end of Long Island, NY. Much of this expansion has been natural, although aided by a deliberate reintroduction project in southeastern Massachusetts in the 1970s. Today eiders are still threatened by over-exploitation in some areas, as well as contaminants (including oil spills) and disease, but their population seems secure in New Hampshire and the southern portion of their range.