Variation in Physiology and Energy Management of Wintering White-Winged Scoters in Relation to Local Habitat Conditions

[摘要] Abstract. Along the Pacific coast of North America, White-winged Scoters (Melanitta fusca) winter in sites that vary widely in habitat conditions. This habitat variation likely alters the relative costs and benefits of using specific sites in terms of factors such as foraging conditions, degree of predation danger, and thermoregulatory costs. To assess how White-winged Scoters adjust their physiology and energy management in response to variation in habitat conditions, we contrasted overwinter dynamics in several physiological indicators across five sites in British Columbia and Washington. We tested the relative support for various hypotheses that considered exposure to wind and waves, water depth, predation danger, diet composition, and collection period as possible underlying causes of variation in physiological indicators. Total body mass and lipid mass were highest at an exposed offshore site, which may reflect an adaptive response to buffer against unpredictable foraging conditions and increased the...

[学科分类] 动物科学

[关键词] body condition;digestive morphology;energy management;Melanitta fusca;physiology;plasma metabolites;White-winged Scoter;wintering habitat