Life on the edge: gastrointestinal parasites from the forest edge and interior primate groups

Abstract

Humans are responsible for massive changes to primate habitats, and one unanticipated consequence of these alterations may be changes in host-parasite interactions. Edges are a ubiquitous aspect of human disturbance to forest landscapes. Here we examine how changes associated with the creation of edges in Kibale National Park, Uganda, alter the parasite community that is supported by two species of African colobines: the endangered red colobus (Piliocolobus tephrosceles) and the black-and-white colobus (Colobus guereza). An analysis of 822 fecal samples from edge and forest interior groups revealed no difference in the richness of parasite communities (i.e., the number of parasite species recovered from the host's fecal sample). However, for both species the proportion of individuals with multiple infections was greater in edge than forest interior groups. The prevalence of specific parasites also varied between edge and forest interior groups. Oesophagostomum sp., a potentially deleterious parasite, was 7.4 times more prevalent in red colobus on the edge than in those in the forest interior, and Entamoeba coli was four times more prevalent in red colobus on the edge than in animals from the forest interior. Environmental contamination with parasites (measured as parasite eggs/gm feces) by red colobus from the edge and forest interior differed in a similar fashion to prevalence for red colobus, but it did not differ for black-and-white colobus. For example, egg counts of Oesophagostomum sp. were 10 times higher in red colobus from the edge than in those from the interior. The less severe infections in the black-and-white colobus relative to the red colobus may reflect the fact that black-and-white colobus raid agricultural crops while red colobus do not. This nutritional gain may facilitate a more effective immune response to parasites by the black-and-white colobus. The fact that animals on the edge are likely not nutritionally stressed raises an intriguing question as to what facilitates the elevated infections in edge animals. We speculate that interactions with humans may be linked to the observed patterns of infections, and hence that understanding the ecology of infectious diseases in nonhuman primates is of paramount importance for conservation and potentially for human-health planning.

How many species of whipworms do we share? Whipworms from man and other primates form two phylogenetic lineages

“…Such a tentative placement may imply the broad zoonotic cross-transmission between non-human primates and humans (e.g. Munene et al 1998, Chapman et al 2006, which can be misleading in most cases. In contrast, limited experimental data have demonstrated the zoonotic transmission of T. trichiura between non-human primates and man Usui 1985, Imada et al 1986).…”

“…Trichuris lemuris Rudolphi, 1819 and Trichuris cynocephalus Khera, 1951 are together with Trichuris trichiura (Linnaeus, 1771) species described from primates (Khera 1951, Chabaud et al 1964. Since infections with whipworms in primates were usually diagnosed as those caused by T. trichiura (see Ooi et al 1993, Reichard et al 2008, Lee et al 2010, several authors have expected zoonotic cross-transmission between non-human primates and humans (Munene et al 1998, Chapman et al 2006.…”

Primate Populations and Their Interactions with Changing Habitats

“…Accordingly, by increasing human contact with nonhuman primates via forest fragmentation, we also run the risk of exposing ourselves to new diseases. However, more recent literature suggests that we should be cautious in accepting the aforementioned scenario (Chapman et al 2006c). …”

First parasitological survey of Endangered Bornean elephants Elephas maximus borneensis

“…In 2012 for the very first time, a chapter in a conservation textbook was dedicated to links be tween habitat loss, habitat fragmentation and infectious disease ecology (Suzan et al 2012). Habitat loss and fragmentation can affect infection dy namics via a variety of mechanisms, including hindering animal movement, impeding gene flow (Coulon et al 2004), facilitating edge effects (Chapman et al 2006a), introducing environmental contamination (Deem et al 2001), altering the ecology of intermediate hosts (Page et al 2001), changing host population size and density (Mbora & McPeek 2009), limiting nutrition (Chapman et al 2006b), facilitating contact and conflict with people (Nelson et al 2003), and subjecting animals to psychological and physiological stress, thereby affecting immunocompetence (McCallum & Dobson 2002). Parasites have the potential to be used as indicators of stress in wildlife threatened by habitat fragmentation (Schwitzer et al 2010).…”