Gastrointestinal Parasites of Black Lion Tamarins (Leontopithecus chrysopygus) Along a Gradient of Anthropogenic Disturbances

Monitoring wildlife health at human-wildlife interfaces is becoming increasingly important, particularly as spatial overlap between humans and wild species is projected to double across 46.5% of global land areas by 2070. Understanding how anthropogenic disturbances influence parasitism in endangered wildlife is therefore essential for both public health and conservation.
This study investigated, for the first time, gastrointestinal parasite infections in wild black lion tamarins (BLT - Leontopithecus chrysopygus) across four sites with contrasting levels of anthropogenic disturbance in São Paulo State, Brazil. Disturbance levels were quantified using the newly developed Human Disturbance Index (HDI; range 0.225–0.913). Fecal samples were collected from six BLT groups and analyzed for gastrointestinal parasites using three complementary coproparasitological techniques (Willis, 1921; Faust et al., 1938; Hoffmann, Pons and Janer, 1934).
Out of 124 samples, 36% were positive for gastrointestinal parasites, with 14% showing multiple infections. Helminth eggs were detected from the superfamilies Oxyuroidea (23.3%), Spiruroidea (15.8%), Rhabditoidea (9.7%), Trichuroidea (4.4%), Ancylostomatoidea (3.8%), Ascaridoidea (1.7%), as well as Cestoda (1.7%). Acanthocephalans (Acanthocephala, 1.1%) and protozoa were also detected, including oocysts of Coccidia (6.1%) and cysts of the family Entamoebidae (3.3%). Preliminary analyses of parasite richness (GLMM Poisson) and prevalence (GLMM binomial) did not reveal statistically significant differences among study sites or between sexes (all p > 0.05). Parasite richness was significantly lower in spring (Mid-September to mid-December, p = 0.033). Ongoing analyses are further evaluating how gastrointestinal parasite infections vary along the human disturbance gradient, using HDI values to quantify anthropogenic disturbance across study sites.