The return of giant otter to the Baniwa Landscape: A multi-scale approach to species recovery in the middle Icana River, Northwest Amazonia, Brazil

摘要

Commercial hunting for the 20th century international fur trade was responsible for the collapse of giant otter populations throughout Amazonia. Some thirty years after the wildlife trade was outlawed, giant otter populations have begun to show signs of recovery. The Baniwa indigenous people from the Upper Rio Negro region of Brazil have witnessed the recovery of otter populations in areas where they had been wiped out by hunting. To evaluate the giant otter recovery process, we identified local and landscape variables contributing to the re-establishment of the species throughout Baniwa territory. We conducted transect sampling in lakes and streams in search of direct and indirect signs of giant otter occurrence. During surveys, we recorded three local variables, and through radar and satellite image, obtained six landscape variables in buffers of 250 m, 500 m and 1000 m. Using generalized linear models we identified the 250 m buffer as the most suitable scale within which to study giant otter habitat use. Connectivity between shallow and elongated waterbodies were the most reliable landscape indicators of otter population presence on the middle Icana River. Our results highlight the importance of small and connected water bodies to species recovery, a fact that should be taken into consideration in the creation of protected areas and local resource management plans. With this study we hope to contribute to the advancement of giant otter conservation strategies, as well as to an increased role for indigenous people in managing their territory and resources towards more effective biodiversity conservation.