Hypothermia as an adaptation for energy conservation during periods of malnutrition

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In marine ecosystems, climate change may result in reduced food availability and increased severe weather events. Animals living under these conditions need to adapt the physiological processes that are crucial to the growth, survival, and reproductive fitness. One fundamental process in ecological energetics is thermoregulation, and petrels use hypothermia in response to malnutrition. The aim of the present study is to enhance our understanding of the adaptation of seabirds to predictable and unpredictable variability in provisioning, by investigating thermoregulation patterns of incubating (fasting) adults that undergo predictable reductions in body reserves, and nestlings that depend on parental provisioning and thus experience unpredictable variability in body reserves. We will identify thermoregulatory adaptations that help nestlings depending on infrequent feedings to achieve a positive energy balance, and will study adult thermoregulation during key events in the annual cycle, namely fasting during incubation and the hatching of the chick. Using RFID temperature recording and CaloBox metabolic rate measurements, we will determine how much energy can be saved by lowering body temperatures. We will also determine what consequences this will have for the development of the nestling. As model species for the study of hypothermia we will study Thin-billed prions, a small seabird species breeding in cold weather conditions and subject to fluctuating food availability in the sub-antarctic marine environment.