LAUSR

The study of intestinal parasite communities is an important aspect of conservation biology, disease ecology, and wildlife health. Researchers can use the presence of select micro- and macroparasites as an indicator of host health. Only two studies have sampled intestinal parasites in free-ranging Aotus monkeys despite their wide geographic distribution in Central and South America. We therefore conducted a survey of gastrointestinal parasites using 50 fecal samples from seven free-ranging black-headed night monkey (Aotus nigriceps) groups at three field sites in the Peruvian Amazon. We calculated an index of habitat quality using Gentry transects and compared this with parasite communities. We recovered seven intestinal parasite taxa: Strongyloides sp.; Balantioides sp.; Trypanoxyuris sp.; Entamoeba sp.; and unidentified species of ascarid, strongylid, and trematode. Two of these taxa have previously been described in captive Aotus nigriceps (Balantioides sp. and Strongyloides sp.). Parasite richness ranged from zero to five taxa with a mean of 0.8 parasite taxa (±1.0 SD) per fecal sample. Fifty-six percent of samples had at least one intestinal parasite taxon. We found all seven parasite taxa in the wet season but only Strongyloides sp. and Trypanoxyuris sp. in the dry season. Balantioides sp. was positively associated with both Entamoeba sp. and an unidentified trematode, while Entamoeba sp. was positively associated with the unidentified ascarid (P < 0.05). Extrapolations support the likelihood of recovering additional intestinal parasite taxa with increased sampling effort. Neither group size nor basal area was significantly associated with parasite richness. These results highlight the need for continued surveillance of Aotus parasites both temporally and across heterogeneous landscapes because several of the parasite taxa we found are pathogenic in nonhuman primates and people.