Adaptive changes of mitochondrial bioenergetics and glucocorticoids in different environmental gradients
Individuals vary significantly in how they respond to energetic challenges. Generally, baseline glucocorticoid levels increase in response to an increased work-load, but individuals differ in the degree of this response. One explanation is that trade-offs between immediate survival and fitness are resolved differently in accordance with an individual’s physiological condition, such as metabolic efficiency and organismal energetic state. To see how these energetic challenges play out in “real life”, I study birds in aviaries and in the field, i.e. starlings trained to fly in a wind tunnel, racing pigeons freely flying home from different locations and great tits exposed to natural variation in energetic demands.