The ASLC houses captive research flocks of both Steller’s and spectacled eiders, which are listed as threatened under the US Endangered Species Act.
At this time of the year, the eiders have been exhibiting courtship behaviors and building pair bonds, and the chosen breeding pairs of the season will be moved into breeding units. But before birds are moved, a lot of preparation needs to happen.
The outdoor pens (commonly referred to as ODLs for ‘outdoor laboratories’) are transformed into a “tundra” breeding habitat and birds are moved from one large flock to smaller groups and pairs. This transformation seeks to imitate the change in habitat and social structure that wild birds undertake from wintering grounds to arctic breeding grounds. These changes help to encourage natural breeding behaviors in the captive birds.
Depending on the goals of the eider breeding season each year, 5 to 12 pairs are selected, and a corresponding number of pens will be converted to breeding units. Nesting areas are created to feel as natural as possible. This involves placing driftwood pieces of various sizes, moss and fake plastic vegetation, and nesting boxes of various designs.
At the beginning of May, breeding pairs are moved into breeding units, and a few weeks later the first egg usually arrives. Typically, the first spectacled eider egg arrives mid May with the first Steller’s eider egg a week or two after.
We continue to promote natural breeding behaviors, which hopefully results in a hen successfully incubating her clutch.
With each passing year, the research flock of Steller’s and spectacled eiders continue with successful breeding seasons (check out more about this project here).
Written by: Sadie Ulman, with Nathan Bawtinhimer (Eider Coordinator) and Emily Johnson (Animal Care Technician)