PATTERNS AND PROCESS OF PARASITE INFECTION AND TRANSMISSION
Open Access
- Author:
- Grear, Daniel A
- Graduate Program:
- Ecology
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- April 27, 2011
- Committee Members:
- Peter John Hudson, Dissertation Advisor/Co-Advisor
Peter John Hudson, Committee Member
Victoria Anne Braithwaite Read, Committee Chair/Co-Chair
Isabella Cattadori, Committee Member
Walter Matthew Tzilkowski, Committee Member - Keywords:
- Peromyscus leucopus
sex-biased transmission
testosterone
trophic interactions
white-footed mouse
transmission dynamics
contact networks
foraging behavior
eastern chipmunk
Tamias striatus
Taylor’s power law
macroparasite dynamics - Abstract:
- The major theme of my dissertation research is how the mechanisms that determine infection and transmission are linked. It is important to note that these two questions are intimately related because infection is necessary to generate transmission and transmission is necessary for new infections. The hypotheses I tested to address these questions build on previous evidence that male hosts are more heavily infected across most host and parasite taxa and also can drive transmission of several types of parasites. I set out to test several hypotheses that explain male-biased transmission, 1) Male hosts have higher transmission rates because they have a greater infection rate and produce infectious stages in proportion to their parasite intensity, 2) Male hosts have higher transmission rates because the parasites they harbor are more fecund, thus producing more infectious stages per parasite, 3) Male hosts have higher transmission rates because their behaviors cause infectious stages to more efficiently infect susceptible hosts. While maleness is a particular focus of my research, I believe that the mechanisms driving transmission can apply more generally. I used field experiments to refine and test the hypotheses set out above in a replicated and randomized before-after-control-impact experimental framework. A focus of these experiments was on the mechanisms of exposure that lead to transmission heterogeneities. Specifically, what is the contribution of behaviorally mediated exposure and between-host interactions to generating transmission heterogeneities? To explicitly examine the role of exposure in transmission dynamics, I incorporated network theory into the design and analysis of several of my experiments. The use of network theory provided unique insights into how the role of behaviorally-mediated exposure influences transmission.