In what could help secure the future of the threatened Steller’s eider in the North Pacific, the biological team at the Alaska SeaLife Center has successfully bred a pair of the rare sea ducks at the research facility in Seward.
The single duckling may be the first Steller’s eider ever produced in captivity in North America, according to a story posted by the center.
Once plentiful in Arctic and western Alaska, Steller’s eiders were listed as threatened under the federal Endangered Species Act after their numbers plunged for unknown reasons. There might be only a few hundred breeding adults left on Alaska’s North Slope outside Barrow, and only a few score haunting the tundra of Western Alaska.
Since the early 2000s, SeaLife center biologists have been studying behavior, physiology and genetics of Steller’s eiders and the equally threatened spectacled eiders in a special habitat built on the center’s outside deck overlooking Resurrection Bay. The center’s ambitious eider program took an approach similar to the center’s study of marine mammals — unlock the physiological secrets of endangered critters by studying them in natural enclosures.
While the spectacled eiders came from breeders in the lower 48, the Steller’s eiders had to be captured out in the Aleutian Chain near Unalaska. From the first, the birds were more skittish and it was clear they would adapt well enough to breed.
“This successful event shows that we have the capability of breeding Steller’s eiders in captivity at the SeaLife Center facility,” says University of Alaska Fairbanks/Alaska SeaLife Center Eider Program Manager, Dr. Tuula Hollmen, in the Sealife story.
“We have taken one big step forward in developing methods and capacity to support recovery efforts for this species.”
Here’s more from the Alaska SeaLife story by Jason Wettstein:
Partners in the eider studies and captive breeding program include the U.S. Fish and Wildlife Service, Dry Creek Waterfowl of Washington, and the North Slope Borough of Alaska.
Steller’s eiders face multiple threats in the wild including predation of eggs and ducklings, contaminant exposure, ingestion of lead shot left over from hunting, habitat changes, harvesting, food limitations, and collision with human made structures.
Steller’s eiders have also met with poor breeding success in Alaska over several years. Even in Barrow, the core breeding area for the Alaska breeding population, the eiders have not been found to nest every year. Since 2005 the Center has been learning how to increase success in wild nests through captive breeding experiments.
Knowledge gained through successful breeding at the Center may aid in captive breeding and in planning for establishing genetic reservoirs of birds. Knowledge derived from breeding also will help researchers better pinpoint the most pressing threats to wild eiders.
A Patient Journey to Egg and Duckling
Mike Grue, aviculturist at the Alaska SeaLife Center was performing his daily checks on the Steller’s eiders on the morning of June 6th when he discovered the olive-green eider egg in one of the breeding pens for the eiders. Soon he was asking fellow aviculturists if someone was trying to play tricks on him.
While the finding of the eider egg was surprising for caretakers, it also was expected after years of patient day to day testing of hypotheses and methods for breeding.
“After four years of professional work, we knew the viable egg would come someday,” says Hollmen. “But the day the egg came was still a welcome, happy day.”
Steller’s eiders eggs are approximately the size and weight of an extra-large chicken egg. There are few established protocols for captive health care, husbandry or breeding in regard to Steller’s eiders.
Center staff attempted a variety of techniques to breed the eiders including providing space to single pairs, encouraging flock environments, mimicking a spring migration by moving birds at particular times, and providing a variety of nest materials similar to those found on the eiders’ tundra home.
Researchers at the Center worked with both wild and captive birds. Solo’s mother was raised in captivity at the center, which may have made it easier for her to breed in the familiar captive surroundings. By providing nest areas about 8 inches off the ground, avian staff mimicked the raised ridges of tundra on which the ducks sometimes breed.
The mother eider is only two years old. She met the male bird only 30 days before laying her first egg.
Surprisingly, she laid 23 eggs total — one clutch of 15 and one of eight. The maximum known number of eggs found in one clutch in the wild is nine. The high productivity of the mother duck is welcome news for eider researchers as they work to discover ways to conserve wild populations.
Center researchers also discovered that foster care was viable. The mother duck did not demonstrate an inclination to care for the duckling, and the duckling was fostered to an adult female that was willing to adopt her.
“It was one of our research goals to determine whether a duckling could be fostered to non-laying females,” says Cline. “This was an unknown.”
“We have been thrilled about the successful fostering,” says Hollmen. “As far as we know, it has not been done before with eiders, and the success holds promise for adding methods to our tool box.”
Steller’s eiders typically weigh under 2 pounds, or between 600 and 900 grams. Males have white heads with greenish tufts and small black eye patches, a black back, and white shoulders. Females are mottled dark brown.