Livros e Publicações
URI permanente para esta coleçãohttps://bdc.icmbio.gov.br/handle/cecav/1481
Navegar
2 resultados
Resultados da Pesquisa
Item Extinction risk evaluation and population size estimation of Bothrops insularis (Serpentes: Viperidae), a critically endangered insular pitviper species of Brazil.(South American Journal of Herpetology, 2021) Abrahão, Carlos Roberto; Amorim, Ligia Grazzielli; Magalhães, Adriana Melo; Azevedo, Carlos Renato; Grisi-Filho, José Henrique Hildebrand; Dias, Ricardo AugustoThe golden lancehead pitviper (Bothrops insularis) is a critically endangered species endemic to the Queimada Grande Island, a federally protected area located 33 km off the southern coast of São Paulo State, Brazil. Adults have specialized diet, preying upon migrating birds, and the species' reproductive efficiency is quite lower than its continental related species, B. jararaca. Potential threats to B. insularis include illegal removal, introduction of exotic species or diseases, and catastrophic events such as wildfire. The population size of B. insularis was estimated at 2,899 individuals (CI 95% = 1,903; 4,416) in its forested habitat using distance sampling. This is the first population estimation using 3D area model for a reptile habitat. Bothrops insularis was more sensitive to harvesting of few individuals yearly than a catastrophic event that causes mortality over 95% of the entire population in a 100-year simulation period. Prioritizing conservation efforts of reptile species in Brazil depends on simple yet robust monitoring methods like the one presented here. This study was only made possible through the concatenation of government, management, and scientific interests. Such synergism should be encouraged in conservation policies in Brazil, especially in remote locations.Item Assessing Brazilian turtles’ vulnerability BY USING species distribution models AND dispersal constraints(Biodiversity and Conservation, 2024-01-27) Pinto, Hugo Bonfim de Arruda; Valadão, Rafael Martins; Andrade, André Felipe Alves de; Batista, Flavia Regina de Queiroz; Marco Júnior, Paulo DeMost assessments of the conservation status of Brazilian turtles use the IUCN geographic range criteria performed by the Minimum Convex Polygon (MCP). This technique often leads to over- or under-estimating the geographic distribution of rare, vulnerable, or endangered species. We aimed to demonstrate that using Species Distribution Models (SDM) on the geographic range assessment of turtles could be more accurate than using the minimum polygon convex. We reduced overestimation of species’ extent of occurrence by adding dispersal constraints, which avoids under- or over-estimating the impact of threatening events. The extent of occurrence derived from MCP was 31% higher than SDM on average, ranging from 4 to 311% higher. Using remaining habitat variables, we found that habitat loss within the predicted extent of occurrence increased by 79% from 1985 to 2019, and inferred population fragmentation increased by 161%. The distribution of turtles Acanthochelys radiolata, Acanthochelys spixii, Hydromedusa maximiliani, Hydromedusa tectifera, Mesoclemmys vanderhaegei, Phrynops williamsi, and Ranacephala hogei is severely fragmented, with most of their extent of occurrence being split into patches that are unavailable to the species persistence. Our findings highlight the importance of using SDM combined with dispersal constraints, which may further benefit from future information about the dispersal capacity of turtles. Furthermore, adding environmental layers to this combination makes it possible to discuss processes affected by habitat fragmentation, such as the fragmentation of species populations, an aspect essential to evaluate population viability and local extinctions.