XXIII Italian Association of Primatology Congress. Trento, Italy, September 14-16, 2017: Abstracts (original) (raw)
Related papers
2017
Sulawesi endemic Macaca maura is included in the IUCN Red List as Endangered due to anthropogenic disturbance and fragmentation of its habitat. Residual populations have a scattered distribution in the karst forests of south Sulawesi. Here the dissolution of limestone layers has created a multi-level landscape hardly accessible for ground predators and humans. In this study, we aimed to obtain better knowledge on the ecological flexibility of M. maura in the use of such a complex habitat, and its consequences on health status. Since all data published on M. maura were obtained from a single group (group B), an additional group (G) was habituated to human presence. We analysed 50 vegetation plots (10 × 20 metres) to discriminate structural features in terms of feeding options (e.g. key food species diversity, density and DBH) and anthropogenic disturbance (e.g. human trails and solid litter). We then correlated these data with habitat use and helminth infection. We collected 74 faecal samples from 18 different adult individuals belonging to both groups. Vegetation analysis suggested that there were 2 suitable habitats: a Ground Forest (e.g. higher abundance of key food species) and a Karst Tower Forest (e.g. lower presence of human trails and solid litter). Gastrointestinal investigation revealed a positive correlation between the prevalence of Trichuris sp. and time devoted to ground food-related activities in all individuals (Spearman correlation, rs = 0.665, p = 0.003). Moreover, behavioural data confirmed that group B, the larger study group of the area, spent most of its activity time in the Ground Forest (N group B = 33 ± 1; N group G = 18 ± 1; χ 2 = 134.30, d.f. = 1, p < 0.001). Since resource availability and predation risk can influence foraging decisions and, ultimately, space use, the "group size effect" might explain the significantly higher proportion of time spent by group B in the Ground Forest. Consequently, due to the Trichuris faecal-oral contamination life-cycle, the chance of infecting individuals based on their feeding habits might be described according to the "soil-transmitted helminthiasis hypothesis".
2017
Sulawesi endemic Macaca maura is included in the IUCN Red List as Endangered due to anthropogenic disturbance and fragmentation of its habitat. Residual populations have a scattered distribution in the karst forests of south Sulawesi. Here the dissolution of limestone layers has created a multi-level landscape hardly accessible for ground predators and humans. In this study, we aimed to obtain better knowledge on the ecological flexibility of M. maura in the use of such a complex habitat, and its consequences on health status. Since all data published on M. maura were obtained from a single group (group B), an additional group (G) was habituated to human presence. We analysed 50 vegetation plots (10 × 20 metres) to discriminate structural features in terms of feeding options (e.g. key food species diversity, density and DBH) and anthropogenic disturbance (e.g. human trails and solid litter). We then correlated these data with habitat use and helminth infection. We collected 74 faecal samples from 18 different adult individuals belonging to both groups. Vegetation analysis suggested that there were 2 suitable habitats: a Ground Forest (e.g. higher abundance of key food species) and a Karst Tower Forest (e.g. lower presence of human trails and solid litter). Gastrointestinal investigation revealed a positive correlation between the prevalence of Trichuris sp. and time devoted to ground food-related activities in all individuals (Spearman correlation, rs = 0.665, p = 0.003). Moreover, behavioural data confirmed that group B, the larger study group of the area, spent most of its activity time in the Ground Forest (N group B = 33 ± 1; N group G = 18 ± 1; χ 2 = 134.30, d.f. = 1, p < 0.001). Since resource availability and predation risk can influence foraging decisions and, ultimately, space use, the "group size effect" might explain the significantly higher proportion of time spent by group B in the Ground Forest. Consequently, due to the Trichuris faecal-oral contamination life-cycle, the chance of infecting individuals based on their feeding habits might be described according to the "soil-transmitted helminthiasis hypothesis".
Four Chimpanzees (Pan troglodytes verus): From a Human-Like Life to a Good Captive Chimp-Like Life
Folia Primatologica, 2017
Sulawesi endemic Macaca maura is included in the IUCN Red List as Endangered due to anthropogenic disturbance and fragmentation of its habitat. Residual populations have a scattered distribution in the karst forests of south Sulawesi. Here the dissolution of limestone layers has created a multi-level landscape hardly accessible for ground predators and humans. In this study, we aimed to obtain better knowledge on the ecological flexibility of M. maura in the use of such a complex habitat, and its consequences on health status. Since all data published on M. maura were obtained from a single group (group B), an additional group (G) was habituated to human presence. We analysed 50 vegetation plots (10 × 20 metres) to discriminate structural features in terms of feeding options (e.g. key food species diversity, density and DBH) and anthropogenic disturbance (e.g. human trails and solid litter). We then correlated these data with habitat use and helminth infection. We collected 74 faecal samples from 18 different adult individuals belonging to both groups. Vegetation analysis suggested that there were 2 suitable habitats: a Ground Forest (e.g. higher abundance of key food species) and a Karst Tower Forest (e.g. lower presence of human trails and solid litter). Gastrointestinal investigation revealed a positive correlation between the prevalence of Trichuris sp. and time devoted to ground food-related activities in all individuals (Spearman correlation, rs = 0.665, p = 0.003). Moreover, behavioural data confirmed that group B, the larger study group of the area, spent most of its activity time in the Ground Forest (N group B = 33 ± 1; N group G = 18 ± 1; χ 2 = 134.30, d.f. = 1, p < 0.001). Since resource availability and predation risk can influence foraging decisions and, ultimately, space use, the "group size effect" might explain the significantly higher proportion of time spent by group B in the Ground Forest. Consequently, due to the Trichuris faecal-oral contamination life-cycle, the chance of infecting individuals based on their feeding habits might be described according to the "soil-transmitted helminthiasis hypothesis".
Habitat disturbance disrupts the ecological interactions of mammals, leading to negative consequences for biodiversity. In particular, it is suggested that parasite-host interactions are affected in tropical ecosystems, with parasite diversity reduced as environmental perturbations take place. In this study, we examined whether the disruption of tropical forests affects the presence of parasites in a population of endangered black howler monkeys (Alouatta pigra) that inhabits a highly fragmented landscape in Balancán, Tabasco, Mexico. Our working hypothesis was that increased forest perturbation would negatively affect the incidence of parasitic infections (parasite presence and richness) in black howler monkeys. We conducted a parasitological study and collected stool samples from 65 adult individuals living in 30 forest fragments across a disturbance gradient. We recovered parasite eggs from stool samples using flotation and sedimentation techniques. We selected fragment size and distance from each forest fragment to the nearest village as measures of forest perturbation. We analyzed the effects of forest perturbation on parasite presence and richness using generalized linear models. Other driving factors such as seasonality, host density, and sex were also considered in the models. Gastrointestinal parasite infection was positively related to distance between forest fragments and the nearest human settlement (β = 0.55 ± SE 0.28, z = 2.0, P = 0.05). No effects of fragment size or any other variable considered in the model on the presence of parasite infection were observed. Parasite richness was not affected by any of the measures of forest perturbation, nor by any other variables considered in the analysis. Our findings suggest that an increase in forest perturbation may negatively affect the probability of parasite infection in black howler monkeys, as individuals living in close proximity to human settlements showed a lower presence of parasites. We proposed that the low parasite infection rates recorded in this monkey population reflect synergistic effects associated with both the alteration of the parasite-primate network, as well as the low resilience of parasites to thrive in a disrupted ecosystem. Los disturbios de hábitat alteran las interacciones ecológicas de los mamíferos con consecuencias negativas para la biodiversidad. En particular , se ha observado que en los ecosistemas tropicales las interacciones entre parásitos y primates son afectadas, y la riqueza de parásitos es reducida conforme aumenta el grado de perturbación ambiental. En este estudio exploramos los efectos de la presión antrópica sobre la pre-sencia y riqueza de parásitos gastrointestinales de una población de monos aulladores negros (Alouatta pigra) que habitan un paisaje altamente fragmentado en Balancán, Tabasco, México. Predecimos que un incremento en la perturbación del bosque afectará negativamente medidas de infección parasitaria (presencia y riqueza de parásitos) en monos aulladores negros. Llevamos a cabo un estudio coproparasitológico y colecta-mos muestras fecales de 65 individuos adultos que habitan 30 fragmentos de bosque a lo largo de un gradiente de perturbación. A través de técnicas de concentración por flotación y sedimentación recuperamos huevos de parásitos. Seleccionamos el tamaño de los fragmentos habita-dos por monos y la distancia que existe entre un fragmento y el poblado más próximo como medidas de perturbación del bosque. Analizamos los efectos de la perturbación del bosque sobre medidas de infección parasitaria usando modelos lineales generalizados. Otras variables como la estacionalidad, la densidad de hospederos y el sexo de individuos también fueron consideradas en los modelos. Encontramos que la distancia entre un fragmento de bosque y el poblado más cercano predice positivamente la presencia de infección parasitaria (β = 0.55 ± EE 0.28, z = 2.0, P = 0.05). Ninguna otra variable tuvo efectos significativos sobre la presencia de parásitos. Las medidas de perturbación del bosque y otras variables consideradas no tuvieron efectos significativos sobre la riqueza de parásitos. Nuestros resultados indican que la presencia de parásitos gastrointestinales disminuye en hospederos que habitan fragmentos que se encuentran en cercanía a asentamientos humanos, lo cual sugiere que un incremento en el grado de perturbación del bosque reduce el parasitismo en monos aulladores negros. Proponemos que las bajas tasas de parasitismo observadas en esta población de monos aulladores reflejan una sinergia derivada de la reducción en la conectividad entre pará-sitos y hospederos, y de la poca resiliencia de los parásitos para sobrevivir en un ecosistema altamente transformado.
Forested edges, especially those that border humanized landscapes, provide opportunities for nonhuman primates and people to interact, and such interactions are predicted to alter disease dynamics. Given the rapid expansion of edge habitats globally, understanding changes occurring on edges is important in evaluating primate behavioral ecology and developing conservation plans. Our research investigates predictions concerning how gastrointestinal parasite and stress levels (cortisol) in red colobus and black-and-white colobus (Procolobus rufomitratus; Colobus guereza) in Kibale National Park, Uganda, differ between humanized and nonhumanized forest edges. We found Trichuris sp., an unidentified strongyle, and Strongyloides sp. in the fecal samples. Results did not generally support our expectation that humanized forest edges increase parasite infection and, counter to what we predicted, fecal cortisol did not differ between habitats, suggesting that proximity to edges and/or to humans did not result in increased stress. We conclude that broad habitat classifications, e.g., " humanized, " may be too general to identify consistent differences in parasite infection, as other factors, specific to the parasite (e.g., life cycled), host (e.g., immune systems strength), or environment (e.g., moisture level), likely also play important roles.
Journal of Tropical Ecology, 2007
Parasites are ubiquitous in wild animals, with host-specific life histories considered as major determinants of prevalence and parasite assemblage patterns. It is predicted that habitat differences in logged rain forests influence population performances of small mammals and consequently may change the infection patterns of local animal populations with regard to endo- and ectoparasites. We investigated patterns of helminth species assemblages (Nematoda, Platyhelminthes) in two rat species (Leopoldamys sabanus, Niviventer cremoriventer) and two tree shrew species (Tupaia tana, T. longipes) in three logged and three unlogged rain forests in Borneo by examining 337 faecal samples with non-invasive faecal egg count (FEC). Nematode eggs prevailed in 95% of all samples with up to five (mean 1.9 ± 1.1) morphotypes. Whereas members of Strongylida were most prevalent in L. sabanus, T. tana and T. longipes, Spirurida dominated in N. cremoriventer that revealed at the same time the lowest ave...
Biodiversitas Journal of Biological Diversity
Javan gibbon (Hylobates moloch) and Javan langur (Trachypithecus auratus) are arboreal primates found at Petungkriyono Forest, Central Java, Indonesia. An increase in ecotourism activity in Petungkriyono Forest affected wildlife behavior and forest landscape along the road. Canopy connections separated by the main road is essential for both of these primates They were spotted foraging food and moved across the separated habitat using available canopy. Based on their activity and habitat along the main road, this research is conducted to identify and count the prevalance of soil-transmitted helminth eggs in their gastrointestinal through their feces. A total of 72 Javan gibbon and 46 Javan langur fecal samples were collected under 10% formalin preservation. Fecal samples were examined using the mini-FLOTAC method for Javan gibbon and the flotation method for Javan langur. The results indicate three orders, including Enoplida, Strongylida, and Rhabditida, were found and the prevalence of helminthiasis is 31.94% for Javan gibbon and 47.82% for Javan langur. Eventhough both of these primates helminthiasis prevalance is considered to be low, higher prevalance in Javan langur was caused by its behavior to be less arboreal than Javan gibbon.
Ecological Determinants of Parasitism in Howler Monkeys
Howler Monkeys, 2014
Infectious diseases caused by pathogens are now recognized as one of the most important threats to primate conservation. The fact that howler monkeys ( Alouatta spp.) are widely distributed from Southern Mexico to Northern Argentina, inhabit a diverse array of habitats, and are considered "pioneers," particularly adapted to exploit marginal habitats, provides an opportunity to explore general trends of parasitism and evaluate the dynamics of infectious diseases in this genus. We take a meta-analysis approach to examine the effect of ecological and environmental variables on parasitic infection using data from 7 howler monkey species at more than 35 sites throughout their distribution. We found that different factors including precipitation, latitude, altitude, and human proximity may infl uence parasite infection depending on the parasite type. We also found that parasites infecting howler monkeys followed a right-skewed distribution, suggesting that only a few individuals harbor infections. This result highlights the importance of collecting large sample sizes when developing these kinds of studies. We suggest that future studies should focus on obtaining fi ne-grained measurements of ecological and microclimate changes to provide better insights into the proximate factors that promote parasitism.
2021
ContextAnthropogenic habitat disturbances that affect the ecology and behavior of parasites and hosts can either facilitate or compromise their interactions and modulate the parasite richness.ObjectivesWe assessed if the size of the habitat patch, the composition and configuration of the landscape (forest cover, patch density and mean distance to the nearest patch) and host group size influence the parasite richness of brown howler monkeys (Alouatta guariba clamitans) inhabiting forest fragments immersed in an anthropogenic matrix.MethodsWe collected fecal samples from 60 howler monkey groups inhabiting distinct forest fragments (one group/fragment) from January to July 2019. We used generalized linear models to assess the power of the independent variables in predicting parasite richness at the patch- and patch-landscape scales.ResultsWe found 10 parasite taxa (five basal eukaryotes, four nematodes and one platyhelminth), nine of which also infect humans or domestic animals. Overal...
Impact of human activities on chimpanzee ground use and parasitism (Pan troglodytes)
Conservation Letters, 2012
The potential of human activities, including research, to alter parasite transmission ecology in wildlife is unknown. We examined gastrointestinal parasitism in chimpanzees (Pan troglodytes schweinfurthii) in Budongo Forest, Uganda. Trail use and time spent on the ground was recorded during 10 months of observations in four sites with differing human disturbance. Disturbance was quantified using transect plots (n= 320). Fecal (n= 435) samples were examined for helminth eggs, larvae, and for protozoan cysts. Individuals that spent more time on the ground had more infections and higher intensity infections. Prevalence of 13 parasite species was similar across sites, but percentage of multiple infections and infection intensity differed, as did ground use. Chimpanzees at the long-term research site spent more time on the ground or on human trails. We hypothesize that researcher presence and trail creation may influence ground use, and thereby parasite burden, by altering trade-offs between foraging and predation risk.