Doctor of Philosophy
Date of Defense
Robert E. Ricklefs, Ph.D.
Avian Haemosporida are common, vector-transmitted blood parasites of birds throughout the world. During my dissertation research, I explored how multiple host species respond immunologically to natural infections in the wild (Chapter 1) and to experimental infections in the laboratory (Chapter 2). Despite their tractability as a model host-parasite system and a burgeoning literature on avian Haemosporida, little is known about how their populations interact across large areas (hereafter “regions”). I present data from parasite surveys of birds across eastern North America suggesting that continental parasite populations track host populations across the region, but also that the host breadth of a parasite can be variable across space and time (Chapter 3). Parasite lineages replace each other spatially within a host population, likely due to interspecific parasite competition mediated by host immune systems (Chapter 3). Parasite prevalence is positively related to host abundance within local assemblages (Chapter 4), but within host species across their ranges, prevalence does not vary with abundance (Chapters 3 and 4). Finally, a 12 year survey of parasites and their hosts in the Missouri Ozarks demonstrates that parasite populations vary through time, and that this variability is related to host breadth—specialist parasites (i.e., parasites infecting primarily one host) were more variable than generalist parasites (i.e., parasites infecting multiple hosts; Chapter 5). Overall my dissertation work contributes to the natural history and ecology of avian Haemosporidian parasites and their avian hosts, and to host-parasite ecological and evolutionary theory.
Ellis, Vincenzo Alexander, "RELATIONSHIPS OF HAEMOSPORIDIAN PARASITES TO POPULATIONS OF THEIR AVIAN HOSTS IN EASTERN NORTH AMERICA" (2015). Dissertations. 146.