Meeting Abstract
Temperature is important to breeding birds, as the timing and success of reproduction are largely influenced by climatic conditions. Altricial nestlings, which hatch naked and unfeathered, do not begin independently thermoregulating until the later stages of their development. Nest microclimate has been shown to influence avian growth, however, little work has been done to examine whether excessive heat influences the production of protective molecules in birds after hatching. We manipulated the temperature in eastern bluebird nestboxes to examine if nestlings become stressed in response to heat, and how it affects their physiology, as well as whether feather-degrading ectoparasites are influenced by this increase in temperature. We found that nestlings exposed to elevated temperatures gained less mass over time relative to those that received the sham treatment, and were in worsening body condition over the course of their development. We also examined expression of circulating heat-shock protein 70 (HSP70) to determine if there were differential protective responses to heat. Feather-degrading bacterial loads were quantified to determine whether these ectoparasites thrive under a temperature optimum. Overall, this study will provide valuable insights into how within-nest temperature affects the development and physiology of altricial birds.
