Parasites are ubiquitous and play important roles in structuring communities, yet their diversity and ecology remain underexplored. Metabarcoding methodologies hold the potential to vastly improve our understanding of parasite community ecology, but this potential is only just starting to be realized. In this study, we explored gastrointestinal nematode communities in more than 500 large mammalian herbivore hosts of 18 different species found in sub-Saharan Africa. Using metabarcoding of fecal samples to detect molecular operational taxonomic units (MOTUs) that correspond with parasite genetic diversity, we investigated three broad questions: 1) To what extent do host species identity and phylogeny explain variation in parasite MOTU richness and community composition? 2) Do host characteristics (body size, range size, and social group size) vary with parasite MOTU richness? and 3) How do estimates of parasite MOTU richness compare to species richness estimates calculated from prior non-molecular work?
Results/Conclusions
We found that host species identity explained most of the variation in an individual’s (infracommunity) parasite MOTU richness and community, with evidence of localized phylogenetic signal for equids and some bovids. Furthermore, we found that although estimated parasite MOTU richness at the host species level (component community) bore no relationship to species richness estimates calculated from the literature, our study exposed major knowledge gaps in parasite diversity for several wild species, suggesting that molecular methods, paired with parasitological expertise, can greatly enhance understanding of patterns in parasite diversity. Analysis of hypothesized correlates of parasite richness showed that only host range size was positively associated with infracommunity parasite MOTU richness. Together these findings underscore the potential power of molecular methods to enhance our understanding of parasite richness and community ecology for an important group of globally-threatened hosts.