Breeding Stress of Female Eiders in Maine

Factors Affecting Plasma Concentrations of Prolactin in the Common Eider Somateria mollissima

“…Because female eiders lose 30-40% of their initial body mass during incubation (Korschgen, 1977;Parker and Holm, 1990;Gabrielsen et al, 1991), we studied the relationships between initial (days 1-5) and final (days 21-24) body masses, between the proportion of mass loss during incubation and prolactin levels in the 3 years of the study. In 1998 and 2000, we measured the proportion of mass loss by dividing daily mass loss (g/day), by initial body mass (g).…”

“…Breeding can be a costly activity for capital incubators (which depend entirely on their body reserves) by reducing the chance of adult survival if body reserves are extensively depleted at the end of incubation (Korschgen, 1977). In this case, clutch abandonment may have an adaptive value if the cost of incubation is too high, and if brood abandonment could lead to higher chances of adult survival, and allows future reproductive attempts (Stearns, 1992;Erikstad et al, 1998).…”

“…The common eider Somateria mollissima presents a particular breeding strategy since only the female incubates for 24-26 days (Korschgen, 1977). Therefore, like the male Emperor penguin A. forsteri (Le Maho, 1977), the female eider can be defined as a true capital incubator (Drent and Daan, 1980) since it relies entirely on their body nutrient reserves during incubation.…”

The influence of female age on breeding in the EiderSomateria mollissima

“…Female Eiders rarely leave their nests during the incubation period, and must therefore rely on their body reserves to sustain them during this period (Korschgen 1977). Rates of weight loss during incubation were calculated from the regression of log," female weight against number of days of incubation.…”

DNA double-strand breaks in relation to persistent organic pollutants in a fasting seabird

“…Common eiders feed at a low 95 trophic level (Dahl et al, 2003), and are thus exposed to relatively low concentrations of 96 POPs (Bustnes et al, 2010) compared to other birds feeding at higher trophic levels (Letcher 97 et al, 2010). However, the female common eiders fast for about four weeks during their 98 incubation period, and may lose 30-45% of their initial body mass (BM) (Korschgen, 1977 Agarose plugs for electrophoresis were prepared according to the procedure described 183…”