Landscape spatial configuration influences the richness of howler monkey gut parasites

Abstract

ABSTRACT Habitat loss and fragmentation are landscape-scale processes that affect the dynamics of parasitic infections. Most research on primate-parasite interactions has focused on the patch-scale, compromising inferences at the landscape level. We investigated the influence of landscape composition and configuration on the richness of gastrointestinal parasites infecting howler monkeys (Alouatta spp.). We compiled published data on howler monkey parasite richness and analyzed them from a landscape perspective. We established a screening process to include only studies on free-ranging howlers that included a detailed map or a description of the sites. Then, we created land cover maps using satellite images and applied generalized linear models to assess the influence of forest cover, matrix impermeability, patch density, edge density, and mean Euclidean distance to the nearest forest fragment on parasite richness and the occurrence of the most prevalent parasites. Edge density and patch density affected parasite richness negatively. Landscape configuration has a stronger effect on the parasites infecting howler monkeys than its composition. The effects of forest edges and patch density on parasite richness are likely promoted by changes in the abiotic conditions necessary for the survival of the free-living stages of parasites or the survival and reproduction of vectors and intermediate hosts.