Técnicas de amostragem e a detecção de mamíferos terrestres na Floresta Amazônica.

Abstract

Though used extensively the diurnal line-transect census method does not provide high quality information on the occurrence and abundance of many mammal species in the Amazonian forest, especially for larger and less abundant species. This study evaluated the effectiveness of diurnal line-transects with nocturnal line-transects and camera traps to detect terrestrial mammals in the forest. Research was carried out on seven 4km-transects at the Uacari Sustainable Development Reserve, on the Juruá river (Amazonas state, Brazil). Nocturnal surveys provided poor information for all species, except for pacas. Tracks accounted for 50% of the observations recorded during diurnal surveys, which was the most effective method for smaller diurnal species and ungulates. For armadillos and rare species camera traps were the most effective technique. Camera traps also provided acceptable results for pacas and smaller diurnal species. Nonetheless all methods failed to accurately represent the most common specie. Combining sampling methods and using statistical analyses that enable the integration of different source data, such as photos, tracks and visual sightings, might be a necessary step to maximize efficiency of studies with mammal populations in the Amazonian forest.