Adapting a Traditional Hunting Technique to Improve Capture Rates for the Endangered Yellow-Footed Tortoise (Chelonoidis denticulatus) during Ecological Surveys in Amazonia

Abstract

The lack of cost-effective methods to detect game species in tropical forests hinders reliable assessments of their population status and the planning of effective actions for their sustainable use. Tortoises are among the most hunted species in Amazonia, but present low detectability in the wild when using current scientific methods. Traditional hunters in the region use specialized methods to capture tortoises, and such knowledge could provide useful insights for improving monitoring methods and, thus, scientific research on this species. Here, we compare the capture rates and cost-effectiveness of two methods to capture the endangered yellow-footed tortoise ( Chelonoidis denticulatus) in Amazonia: the conventional active search and an adaptation of pitfall traps using attractive baits employed by Indigenous and non-Indigenous people to hunt tortoises. We sampled 40 sites in upland forests and whitewater flooded forests during the dry and wet seasons in central Amazonia and captured 37 yellow-footed tortoises. The highest capture rate (0.29 tortoises/hour) was obtained using traps in upland forests, fourfold higher than by active search. Traps also presented greater cost-effectiveness than the active search (US$63 vs US$256 per captured tortoise). Our capture rate with traps was 67 times greater than those obtained using line transects in western and northern Amazonia. The success exhibited by this widespread hunting technique is a result of centuries of hunters' traditional knowledge in the Amazon. The unveiling of a cost-effective method for capturing tortoises shows the importance of exchanging traditional and scientific knowledge; efficient capturing methods favor the inclusion of the species in long-term monitoring programs and foster in situ studies that help develop strategies for its conservation.