Meeting Abstract
18.5 Tuesday, Jan. 4 How does social dominance influence seasonal acclimatization and winter metabolic performance in black-capped chickadees ? LEWDEN, A*; VÉZINA, F; Université du Québec à Rimouski (UQAR); Université du Québec à Rimouski (UQAR) agnes.lewden@uqar.qc.ca
With high energy demands and low food availability, winter is a challenging season for resident bird species wintering at northern latitudes. Winter requires seasonal acclimatization, which is often associated with elevated metabolic performance and cold endurance in small birds. In species forming winter flocks however, social rank may add extra energy costs as maintaining a dominant status has been shown to affect organ size and maintenance energy expenditure. Yet, whether social dominance influences acclimatization capacity, winter metabolic performance and cold endurance remains to be investigated. We studied the effect of social dominance on winter metabolic performance (basal metabolic rate, BMR, and thermogenic capacity, Msum) and seasonal acclimatization (individual phenotypic variation between winter and summer) in three flocks of black-capped chickadees (Poecile atricapillus). Birds of known social ranks were caught and measured while expressing both their winter (January to April) and summer (August) phenotypes during 2010. Preliminary results suggest, in contrast to findings in European tit species, that winter metabolic performance is independent of social status in black-capped chickadees.
