Very little is known about eider sea ducks, and the spectacled eider (Somateria fischeri) is no exception. It was not until using satellite transmitters in the mid 1990's, that wintering grounds for the world population of spectacled eiders were discovered between St. Lawrence and St. Mathews Islands in the Bering Sea. Inhabiting sub-arctic and arctic environments, spectacled eiders, like their cousins, live in some of the most remote and extreme environments on earth. Spectacled eider populations inhabit the Yukon-Kuskokwim Delta along the western Alaska, the North Slope of Alaska, and the arctic coast of eastern Russia. Global population estimates vary up to 375,000, the majority of which represents the spectacled eider population breeding in Russia.
All four species of eiders including spectacled, Steller's, common (Somateria mollissima) and king (Somateria spectabilis) eiders declined in numbers from the 1970s to 1990s. In 1993, the U.S. Fish and Wildlife Service (USFWS) listed the spectacled eider as threatened in Alaska. Spectacled eiders have suffered a 96% decline along the Y-K Delta in western Alaska since the 1970’s. It was likely that more than 96,000 birds migrated to this area to breed during the 1970’s, but by 1992, only about 5,000 individuals were reported. Since their listing, numbers have fluctuated from approximately 4,000 to 12,000 per year in western Alaska. Currently, Alaska is the only location where populations are experiencing threatening population declines—the International Union for the Conservation of Nature and Natural Resources (IUCN), has not, as of yet, listed this species as a species of global concern.
Because spectacled eiders are taxonomically similar to other eider species, it is thought that similar factors may be contributing to other eider population declines. It is likely that that a combination of factors are contributing to the decline and lack of recovery which includes habitat loss, contamination, predation, food availability, and hunting. Since 2001, the Alaska SeaLife Center (ASLC) has been investigating several of these cause(s) for the decline, but more importantly, identifying why this species has not recovered from its vulnerable status.
According to priorities set forth by the Eider Recovery Team, a federally appointed team of scientists and managers, the ASLC has implemented an extensive research and conservation program for the recovery of spectacled eiders. In many instances, because of the threatened and critical status of Steller’s and spectacled eiders, surrogate species were also selected for research purposes. Common eiders from our captive flock, as a result, were selected for particular experiments. The ASLC currently maintains a captive flock of 13 spectacled eiders (all adults) for research and conservation purposes.
To learn more about specific projects, click on the topics below.
Reproductive Biology and Physiology Breeding propensity and productivity are critical components of avian population cycles. Declines in reproductive productivity may significantly impact population trends and have already been reported in eiders. Reproductive problems have been documented for both of the threatened species in Alaska. To determine the reproductive status of eiders, scientists at the ASLC are examining the endocrine (hormone) system and metabolic pathways associated with pair formation, mating, follicular development, laying, incubation, and brood rearing. This is an on-going project involving free-ranging and captive flocks of Steller's and spectacled eiders.
Foraging Ecology and nutrition
Prey changes in either abundance, distribution, or availability can play a significant role in eider survivalship. ASLC scientists are developing techniques to evaluate body condition and energetic requirements during the breeding season, determining how eiders forage at deeper recorded depths, and evaluating available prey and its energetic content. In a separate study (called a Request for Proposal—RFP for short) with the U.S. Geological Survey Alaska Science Center (USGS-ASC), a temporary dive column was constructed at the ASLC to quantitatively record and observe foraging behavior of common eiders before, during, and after the implantation of satellite transmitters.
Disease Ecology and Epidemiology Diseases have the potential to cause significant mortalities both indirectly and directly. Very little is known as to what diseases—parasitic, viral, or bacterial—eiders are vulnerable to, and have the potential to being exposed. Alaska SeaLife Center scientists are collecting blood, serum, and tissue samples from wild Steller's and spectacled eiders to identify and isolate any disease agents that may be impacting eiders in the wild.
Contaminants have the potential to affect the growth, reproduction, and development of animals at different age classes. In two separate RFPs, the effects of selenium exposure were examined in common eiders, and sources of lead exposure were determined at the Yukon-Kuskokwim Delta and near Barrow. Scientists are also examining the effects and prevalence of spent lead shot pellets found near known eider breeding, nesting, and foraging sites.
predation It is thought that predation may be a contributing factor to nest failure among Steller's and spectacled eiders. Potential nest predators in the Barrow area include arctic foxes (Alopex lagopus), short-tailed weasels (Mustela erminea), common ravens (Corvus corax), jaegers (Stercorarius spp.), and glaucous gulls (Larus hyperboreus). In a recent RFP, the ASLC partnered with the USFWS to identify nest predators, examine hen and predator behavior, and investigate effects of human activities on Steller’s eider nest success using remote video observation stations.
Conservation initiative In 2005, the Eider Program began developing captive propagation techniques to determine whether such approaches could be used to enhance wild Steller’s eider populations. In total, 25 Steller’s eiders have been reared through our facility—8 in 2005, 16 in 2006, and 1 in 2007. This capacity has led the USFWS to consider ASLC as a captive breeding site for Steller’s eiders—an important conservation initiative to help recover the species from its depleted status. Artificial incubation techniques have also been evaluated in Barrow, Alaska to help enhance egg survival in Steller’s eiders.