A. Status of the Spectacled Eider - U.S. Fish and Wildlife Service

helicopter surveys in the Prudhoe Bay region, expanded to the entire arctic coastal plain
yielded an uncorrected estimate of 16,000 total birds in 1993; this is an underestimate of total
birds because the density of Spectacled Eiders is lower in Prudhoe Bay than in other areas of
the arctic coastal plain (TERA 1993).
Aerial surveys of the eider’s entire current breeding range along the arctic coast of eastern
Russia were conducted in late June 1993 and 1994. Combining data from these surveys
between the Kolyma River and Kolychin Bay (1993)and-Kolyma and Lena River deltas (1994)
suggests that there may be > 140,000 birds in AR (Hodges and Eldridge 1994, 1995).
Life History and Ecology
Life history characteristics include survivorship, fecundity, age at first reproduction, frequency of
reproduction, and lifespan. These traits vary with changes in populations and their environments.
A suite oflife history characteristics can be referred to as a life history strategy.
Important influences on life history strategies of northern sea ducks are the extreme environmental
conditions in both breeding and non-breeding environments and the high degree ofvariability both
within and between these environments. The timing, length and climate ofthe breeding season
varies from year to year in northern regions. Life cycles ofnorthern marine birds (timing of
arrival on breeding grounds, reproductive cycle, and migration) are directly affected by seasonal
changes in the hydrological and hydrobiological conditions (Uspenskii 1984). The timing ofsnow
melt, and the break up ofseasonal ice in marine waters along migration routes and in freshwater
ponds on breeding grounds can vary by several weeks from year to year. This increases the
potential for delayed availability of nesting habitat, reduced clutch sizes, and non-breeding
(Barry 1960, 1967; Cooch 1965; Ryder 1967; Kistchinski and Flint 1974).
Sea ducks must be adapted to life at sea and on land, and to both marine and freshwater
environments. Different strategies for foraging, locomotion, water balance, and thermoregulation
are required in each ofthese environments. Furthermore, life in northern regions requires
specialized adaptations to extreme temperatures and to large variations in weather and
temperature. For example, a northern sea duck must be able to maintain its body temperature in
temperatures from 600F)
during the summer.
Basic life history information is lacking for many ofthe sea duck species. The available
information indicates that sea ducks are long-lived, annual adult survival is high (in a healthy
population), annual recruitment to breeding age is low, annual breeding rates and success is
variable, clutch size is small, and sexual maturity is deferred (Goudie et al. 1994). Ecologists
refer to species with this suite ofcharacteristics as “K-selected” (Wilson 1980). This type of
strategy minimizes the importance ofannual investment in reproduction and maximizes the
importance ofannual survival; population stability is dependent on high adult survival and a few
successful years of reproduction (ibid.).
18