Effects of sea ice on winter site fidelity of Pacific Common Eiders (Somateria mollissima v-nigrum)

Abstract

ABSTRACT. In northern marine habitats, the presence or absence of sea ice results in variability in the distribution of many species and the quality and availability of pelagic winter habitat. To understand the effects of ice on intra- and inter-annual winter site fidelity and movements in a northern sea-duck species, we marked 25 adult Pacific Common Eiders (Somateria mollissima v-nigrum) on their nesting area at Cape Espenberg, Alaska, with satellite transmitters and monitored their movements to their wintering areas in the northern Bering Sea for a 2-year period. We examined changes in winter fidelity in relation to home-range characteristics and ice. Characteristics of polynyas (areas with persistent open water during winter) varied substantially and likely had an effect on the size of winter ranges and movements within polynyas. Movements within polynyas were correlated with changes in weather that affected ice conditions. Ninety-five percent of individuals were found within their 95% utilization dis...