Evidence shows parasites have an aggregate frequency distribution, where only a handful of individuals in the host population are affected. The impacts on those hosts vary in severity but in many avian species, parasites can affect energy expenditure, body condition, and even survival. A better understanding is needed on factors that contribute to parasite abundance and why particular individuals in a population are more susceptible to loading. To date, the majority of parasite sampling on Golden Eagle (Aquilla chrysaetos) nestlings has been done by manual examination, a technique best suited for slow moving or stationary species of parasites. In our study, we applied the dust-ruffling technique; a method that has shown to have a higher rate of return than manual examination in passerines. In addition to sampling for parasite richness, intensity, and abundance, we will be examining abiotic factors (temperature and relative humidity) of the nest site with iButton data loggers. We will also be monitoring nests with camera traps to document adult attendance, anti-parasite behavior, and prey selection and availability. By monitoring behavior and nest site characteristics, we hope to identify specific variables that contribute to host selection. In the spring of 2019, a small pilot effort was completed on eight Golden Eagles, results are being analyzed. In 2020 and 2021, a large-scale effort at ~30 Golden Eagle nests will take place across western Utah. This research will further refine parasite sampling techniques on large raptors and provide insights into how microsite characteristics influence parasite frequency.
Results/Conclusions
Specimen identification, iButton data analysis, and diet review, are still ongoing but first-season results are expected by August 1st, 2020. From the pilot season, we found that 7 of the 10 Golden Eagle nests sampled contained ectoparasites.