Daily temperature impacts thermogenic flexibility in a high elevation migrant regardless of breeding status

AOS Research Grant Seminar

Presenter: Jessica Karr, Postdoctoral Researcher, University of Massachusetts Amherst; 2024 Josselyn Van Tyne Memorial Research Grant winner

Low temperature and variable precipitation can negatively impact the survival or reproductive success of animals if they generate energetic tradeoffs. However, despite extensive research, very few studies have compared thermogenic tradeoffs in the context of variable weather and breeding status – especially in areas where challenging conditions can occur during the early breeding season. Using a migrant songbird that breeds in the eastern Sierra Mountains, the mountain white-crowned sparrow (Zonotrichia leucophrys oriantha), I tested two hypotheses to determine how thermogenic capacity responded to changes in ambient temperature (Low Temperature Hypothesis) and whether thermogenic capacity influenced the onset of reproduction (Reproductive Tradeoff Hypothesis).