5. Conflito homem-animal – Temas
Benoit De Thoisy, Sébastien Brosse, Cécile Richard-Hansen, Viviane Thierron
Rapid evaluation of relationships between impacts of forest anthropic activities and threats on biodiversity in French Guiana.
Impacts of human activities (hunting, opening of tracks, logging, …) on wildlife are well documented. Nevertheless, methodological tools allowing to locate and quantify the intensity of these impacts at a large geographic scale are still poorly developped. Sanderson et al. (BioScience 2002) proposed a method to map human impacts, based on scores depending of the nature of the activities. A map of human footprint, using these scores adapted to French Guiana and a superimposition of geographic data of human densities, land occupation, tracks, roads, rivers, logging and gold mining activities, was realized. In order to evaluate the reliability of this map to highlight interactions between human activities and biodiversity, the cumulated score of human impacts was crossed with faunistic data on 35 forest sites. Each of these sites was characterized by a human impact score, and was surveyed with the line-transect sampling method. We showed that the human footprint score was negatively correlated to the diversity of primate species, and negatively correlated to the abundance of three sensitive species, the brown capuchin, the red howler, and the black spider monkey. Field observations also allowed to demonstrate a strong correlation between the diversity of the primate community and the total richness of recorded megafauna. Lastly, a distance of 80 km length for the transect effort was confirmed for reliable estimations of the richness and and abundance of monkeys. This work shows the relevance of the study of primate communities as indicator of the megafauna status, and the relevance of a map cumulating human impacts to a rapid identification of areas where biodiversity is threatened.