Parasitism of free-ranging Neotropical primates: examining parasite-host and parasite-parasite relationships

Parasites are infectious agents that require resources from host organisms to complete all or part of their lifecycles. It is customary for wild animals to acquire and maintain multiple parasitic infections during their lifetime. The effects of parasites on hosts vary across demographic and environmental variables, and in relation to each other. Moreover, the propensity for a host animal to acquire an infection can be influenced by other host species in the area that are susceptible to the same parasites. This dissertation describes and explores the natural parasite assemblage of a free-ranging community of nonhuman primates in the Peruvian Amazon rainforest. A mark-recapture program of sympatric saddleback (Leontocebus weddelli) and emperor (Saguinus imperator) tamarins (Callitrichidae) was implemented from June through August, 2012 – 2015, to collect repeat blood and fecal samples from known individuals. Seven other primates on site, belonging to the Pitheciidae, Cebidae, Atelidae, and Aotidae, were followed in 2014 and 2015 for noninvasive collection of fecal samples. Microscopy and molecular techniques were used to assess the degree of parasite–host specificity in gastrointestinal and blood parasites. I also explored individual differences in infection status engendered by various host factors, and tested for non-random associations of co-occurrence between multiple parasites. Patterns of infection were analyzed using multifactorial statistical models. In total, I collected 250 blood samples from 134 known tamarins, 208 fecal samples from 105 known tamarins, and 64 fecal samples distributed across the remaining hosts. Temporal variation of multiple parasite infections confirmed the necessity of a multi-year study to evaluate parasite-host relationships in this system. Individual age was a common predictor of parasite infection, and co-infections were significant predictors for blood parasites. No gastrointestinal parasites appeared to be host specific, but significant differences in prevalence were observed across hosts. I also report the presence of a natural, potentially zoonotic malarial parasite that for first time is demonstrated to chronically infect its nonhuman primate host. Collectively these data demonstrate the importance and need for broad spectrum and long-term screening of parasites from wildlife communities