Understanding the factors that contribute to the prevalence of parasites and disease is an issue of broad significance in ecology, with implications for the health of plants, wildlife, and humans. Key biological factors include species richness, host community composition, the identity of individual host species, and host competence (the proportion of individuals of a species that can maintain and transmit infections). Recent research articles have issued a call for studies that focus on the role of community composition and the identity of individual species in determining parasite prevalence. The goal of this study was to examine how the experimental removal of community-dominant kangaroo rats (Dipodomys spp.) affects the prevalence, intensity of infestation, and community composition of ectoparasites (fleas and ticks). Our study utilized three treatments: i) experimental plots where all rodents had access, ii) experimental plots where kangaroo rats were removed, and iii) the area outside of the study plots.
Results/Conclusions
Our study provides evidence that the removal of community-dominant kangaroo rats affects the prevalence, intensity of infestation, and community composition of ectoparasites. These effects were most pronounced for both the prevalence and intensity of infestation of jackrabbit ticks between the plots where all rodents had access and the area outside of the plots. The prevalence and intensity of infestation of ticks was significantly higher outside of the study plots. Ticks were only found on kangaroo rats; thus, their absence marked the removal of ticks from the parasite community. The community composition and relative abundance of flea species also varied across treatments. Our results underline the potential for community ecology to inform disease ecology, and the value of conducting this work using an experimental approach. Furthermore, our work emphasizes the contribution of host community composition and identity to determining parasite prevalence, underlining that the relationship between biodiversity and disease is only one of many important factors. Given the widespread effects of anthropogenic impact, which disrupts mammalian communities across numerous ecosystems, this study should be of broad significance.