The Role of Disease and Ectoparasites in the Ecology of Nestling Golden Eagles

• Main Author: Dudek, Benjamin Michael
• Format: Text
• Language: unknown
• Published: ScholarWorks 2017
• Subjects: Golden eagle; disease; Trichomonas gallinae; ectoparasite; Haematosiphon inodorus; Biology; Aquila chrysaetos; golden eagle
• Online Access: https://scholarworks.boisestate.edu/td/1289; https://doi.org/10.18122/B2BH8X; https://scholarworks.boisestate.edu/context/td/article/2399/viewcontent/Dudek_Benjamin_Thesis_August2017.pdf

Climate and anthropogenic land use changes can alter biological communities and affect disease infection rates and parasite species distribution and abundance. Management to mitigate the threats of emerging infectious diseases and parasite species requires identifying and understanding factors that influence individual susceptibility within populations. Golden eagles (Aquila chrysaetos) in southwestern Idaho face several current and emerging threats, including a landscape-mediated diet shift that has increased the potential for disease infection, and warming temperatures that may increase the distribution and abundance of hematophagous ectoparasites. We examined prevalence of Trichomonas gallinae infection in golden eagle nestlings across western North America in 2015 and conducted a detailed study of the risk factors associated with T. gallinae infection in southwestern Idaho. We also quantified the abundance of Mexican chicken bug (Haematosiphon inodorus; Hemiptera: Cimicidae) in golden eagle nests in southwestern Idaho in 2015 and 2016. We developed a pit fall trap method to measure H. inodorus abundance, investigated factors that might affect abundance in nests, tested the ‘nest protection’ hypothesis that eagles modify nest sites to reduce the effects of ectoparasitism, and measured the physiological effects of ectoparasitism on nestlings. In our study of T. gallinae, we found a 6% infection rate distributed broadly across our western North America study area, with a relatively high T. gallinae infection rate, 41%, in Idaho. The probability of T. gallinae infection increased as the proportion of rock pigeons in nestling diet increased. Landscape-level change in southwestern Idaho is related to an increase in eagle diet diversity, and an increase in rock pigeons in nestling diet increased the probability of T. gallinae infection. In our study of H. inodorus, we found that eagles reuse less parasitized nests in successive years, and that south-facing nests and nests with later phenology had higher H. inodorus ...