Abordagens metodológicas para avaliar risco de extinção de espécies de Brachyteles (Primates: Atelidae)

• Ano de defesa: 2015
• Autor(a) principal: Gonçalves, Arthur Machado
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Mestrado em Biologia Animal; UFES; Programa de Pós-Graduação em Ciências Biológicas
• Palavras-chave em Português: Geopraphical distribution; Distribuição geográfica; Zoogeografia; Sistemas de informação geográfica; Biologia de conservação; Primata; Extinção (Biologia); Brachyteles; Florestas tropicais; Zoologia; 57
• Link de acesso: http://repositorio.ufes.br/handle/10/1479

The geographical distribution of a taxon is limited by ecological and historical aspects. Many human activities have caused changes in vegetation cover, leading to fragmentation and loss of habitat. This has led to local extinction of populations of various species by altering their geographical distribution. Among them are the two species of the genus Brachyteles (muriquis), which are endemic primates of the Atlantic Forest, one of the most affected biomes by these processes. The International Union for Conservation of Nature (IUCN) is an organization that seeks to conserve biodiversity. Among other criteria, it uses the knowledge of the restricted geographic distributions of species to rank them in threatened categories, the so-called red lists. It uses spatial parameters that indicate the risk of extinction of a particular taxon in relation to their geographical distribution. Often the calculations of these parameters are subjective and it is necessary the search of methods that make the assessments more objective, accurate, and replicable. In this context, we tested different calculation methods of three parameters related to the geographical distribution of B. hypoxanthus and B. arachnoids. They are threatened species with well-known occurrence localities and were deeply affected by the Atlantic Forest fragmentation. Thus, they are potentially a good model for these analyses. We built a database of current occurrence localities of both species. Through Geographic Information Systems (GIS) approaches, we estimated the Extent of Occurrence (EOO) using Minimum Convex Polygons and a-hull, and Area of Occupancy (AOO) and subpopulations using grids, circular buffers and a-hull methods, in different special scales. The results were compared to identify the most appropriate approaches and scales for the assessment of extinction risk. The analyses indicate that the list of localities and maps of IUCN should be updated. Moreover, they suggest that a-hull is an advantageous approach to EOO and the buffer method is the most suitable parameter for AOO and subpopulations, when smaller spatial scales are used. The GeoCAT tool can be used as a preliminary extinction risk assessment based on the geographical distribution criteria for being able to perform instant EOO and AOO analyses, and their results are similar to those of other approaches.