| Popis: |
Previous studies have shown how endothermic organisms have a range of environmental temperatures in which energy used for thermoregulation is relatively low. If the temperature exceeds this specific range, the individual needs to thermoregulate. The demand for thermoregulation depends on several factors, for instance the intensity of solar radiation. Species which have little opportunity to avoid incident solar radiation at their breeding sites, such as cliff-nesting seabirds, could thus be exposed to temperatures outside of their preferred range. In 2019, cameras were installed on the cliffs of Stora Karlsö, which has the Baltic Sea’s largest colony of common guillemots (Uria algee). These cameras made it possible to study the thermoregulatory behavior of common guillemots. Due to seabird species adaptation for minimal heat loss and a rise in global temperature, the common guillemot constitutes an interesting study species. This study aimed to answer the two following questions: How often do common guillemots exhibit thermal regulation? Which variables affect the frequency of thermal regulation in common guillemots? To investigate thermoregulatory behavior and potential drivers, this study included a basic pilot study, behavioral analyzes and regression analyzes to explore potential causal relationships. Due to previous studies five behavior were suggested to indicate thermal regulation in common guillemots of Stora Karlsö; Panting, Raising scapular feathers, “Screaming”, Orientation toward the sun and Seeking shadow. During June 2019, the guillemots showed thermoregulatory behavior 22 of 28 days. Two separate regression analyzes indicate that 18,57 % of the variability of the thermal regulation can be explained by temperature and 84,83 % of the variability can be explained by direct solar radiation. This study observed possible trade-offs and thermal adaptations. |
