Meeting Abstract

71.5  Thursday, Jan. 6  Daily and seasonal variation in markers of nutritional condition in black-capped chickadee: effect of short term climate fluctuations MANDIN, Clément*; VÉZINA, François; Université du Québec à Rimouski; Université du Québec à Rimouski clement.mandin@uqar.qc.ca

Resident passerine species wintering at high latitude must face relatively harsh climatic conditions during the cold season. Several adaptive physiological adjustments, such as daily fattening to support fasting at night, have been documented in response to these seasonal constraints. However little is known on how short-term climatic variations may influence individual nutritional condition, which may in turn affect winter survival. Using black-capped chickadee (Poecile atricapillus) as our model species, we investigated daily and seasonal variation in two markers of nutritional condition (plasma triglycerides, TRIG, an index of fat deposition rate and β-hydroxy-butyrate, an index of fat catabolism) from September 2009 to March 2010. Data was analyzed in light of short-term climatic variations recorded by automated weather stations to identify climatic factors mostly likely influencing the birds’ condition indices. Preliminary results show a daily increase in TRIG, from sunrise to sunset, and suggest that birds are fattening up faster on colder days. Results also indicate a seasonal increase in fat deposition rate culminating in January.