King Eider Foraging Effort During the Pre-Breeding Period in Alaska

The condor

Steffen Oppel¹ 

关键词: behavior;    chironomid;    foraging;    intake rate;    King Eider;    sea duck;    Somateria spectabilis;   

DOI  :  10.1525/cond.2011.100077

学科分类：动物科学

来源: Central Ornithology Publication Office

【 摘 要 】

Abstract. For reproduction, many arctic-nesting migratory birds rely on nutrients obtained on the breeding grounds, so they devote sufficient time to foraging immediately prior to nesting. However, little is known about the increase in foraging effort necessary to meet the energetic requirements of reproduction. In early June 2006 and 2008, we quantified the proportion of time spent foraging before breeding by a large sea duck, the King Eider (Somateria spectabilis), on its breeding grounds in northern Alaska. During >235 hours of behavioral observations, both male and female King Eiders spent >50% of the day loafing (resting, sleeping, comfort behavior, or being alert). Females foraged on average 30% of the time (mean 7.2 hr day-1,95% CI 6.0-8.4 hr day-1), three times as much as males (9%; 2.3 hr day-1, 95% CI 1.5–2.8 hr day-1). The most common prey in ponds where the eiders foraged were chironomid larvae and worms ranging in length from 1 to 30 mm. If the King Eider's daily energy expenditure on its bre...

【 授权许可】

CC BY