Comparative Tests of Parasite Species Richness in Primates

TLDR

Parasite community diversity varies among hosts, and although many factors have been proposed to explain this variation, few studies have compared competing hypotheses across multiple parasite communities within a single host clade. The study tests which of four variable sets—body mass and life history, social contact and population density, diet, and habitat diversity—best predicts parasite community diversity in 101 primate species. The authors compiled 941 host–parasite pairs across 101 primates, defined parasites broadly, and controlled for sampling effort to assess the influence of the four variable sets. Nonphylogenetic analyses found body mass correlated with overall parasite, helminth, and virus diversity, but this effect vanished when phylogeny was accounted for; host population density consistently predicted total parasite, helminth, protozoa, and virus richness, while geographic range size and day range length explained variation in virus diversity.

Abstract

Some hosts harbor diverse parasite communities, whereas others are relatively parasite free. Many factors have been proposed to account for patterns of parasite species richness, but few studies have investigated competing hypotheses among multiple parasite communities in the same host clade. We used a comparative data set of 941 host‐parasite combinations, representing 101 anthropoid primate species and 231 parasite taxa, to test the relative importance of four sets of variables that have been proposed as determinants of parasite community diversity in primates: host body mass and life history, social contact and population density, diet, and habitat diversity. We defined parasites broadly to include not only parasitic helminths and arthropods but also viruses, bacteria, fungi, and protozoa, and we controlled for effects of uneven sampling effort on per‐host measures of parasite diversity. In nonphylogenetic tests, body mass was correlated with total parasite diversity and the diversity of helminths and viruses. When phylogeny was taken into account, however, body mass became nonsignificant. Host population density, a key determinant of parasite spread in many epidemiological models, was associated consistently with total parasite species richness and the diversity of helminths, protozoa, and viruses tested separately. Geographic range size and day range length explained significant variation in the diversity of viruses.