Mammals and their activity patterns in a forest area in the Humid Chaco, northern Argentina

The Humid Chaco has a high mammalian biodiversity. As habitats are threatened due to exploitation and environmental degradation, protected areas can act as refuges for wild animals. In 2006, ca 1,100 ha of gallery forest were established as the “Owl Monkey Reserve” within the private cattle ranch “Estancia Guaycoléc”. The mammalian species richness and composition of the reserve was determined using direct observations, camera traps, and indirect evidence. The camera traps also allowed us to determine the activity periods of 20 of the species. Forty-two species were recorded. A fourth of those species (24%) are categorized under some risk of extinction in Argentina. While most species showed usual activity periods, 2 species (Mazama americana and Tayassu pecari) were not as exclusively nocturnal as reported from other sites, possibly due to reduced hunting pressure. The presence of various endangered species highlights the importance of protected private reserves