Geneviève McHugh
Project
Phenotypic mismatch in cold environment: how do birds compensate for the digestive loss a spare capacity?Respond to varying environmental constraints requires some immediate spare capacity in food intake. Spare capacity makes it possible to quickly increase food consumption in response to an increase in energy demand, to reduce or avoid energy imbalances. Recent studies have demonstrated that immediate spare capacity in food intake decreases with acclimation to colder temperatures in birds. The loss of immediate spare capacity in digestive functions during cold acclimation can be considerable and force compensatory adjustments in other traits to maintain a neutral energy balance. Using the pine siskin (Spinus pinus) as a model, this study aims to identify the physiological mechanisms used to compensate for a lack of immediate spare capacity in food intake, after a sudden drop in ambient temperature. These potential compensatory mechanisms include reducing body temperature and basal metabolism, fluffing up feathers to minimize heat loss, reducing locomotor activity, and increasing digestion efficiency.
