Species richness and areas of endemism of oryzomyine rodents (Cricetidae, Sigmodontinae) in South America: an ndm/vndm approach

Abstract

Aim To infer areas of endemism for the tribe Oryzomyini in South America by employing a database of species richness and geographical distribution, and to compare these results with areas of endemism and species richness proposed in the literature for other taxa. Location We analysed specimens of the tribe Oryzomyini distributed throughout South and Central America, which are housed in European, North and South American museums and collections. Methods We analysed 2768 occurrence records for 102 species of the tribe Oryzomyini using the ndm/vndm algorithm and three different grid sizes to assess the possible effects of grid cell area on the results. Results Using the overlap of consensus areas in South America, we identified three generalized areas of endemism for the Oryzomyini: north‐western South America (NWSA), eastern South American (ESA), and northern South America (NSA); we also identified the Galápagos archipelago (GA) as an area of endemism. Main conclusions Areas of endemism detected in the continental portion of South America include its three main mountain chains: the Andes Cordillera, the Guyanan Shields, and an area east of the Brazilian Shield named Serra do Mar. Each of these regions encompasses many different types of vegetation, and the species richness and composition of the areas of endemism of the tribe are directly related to this environmental diversity. Different grid sizes affected the distributional heterogeneity of the consensus areas. The smallest grid cell size identified mainly Andean areas, which contain a higher number of more exclusive species in a small area along a steep elevational gradient. In contrast, the largest grid size identified areas of endemism along an environmental gradient that co‐varied with latitude and longitude. The identified areas of endemism are corroborated by previous studies on other taxa.

Areas of endemism of arthropods in the Atlantic Forest (Brazil): an approach based on a metaconsensus criterion using endemicity analysis

“…Furthermore, the metaconsensus criterion alowed the identification of highly congruent CAs resulting from different analyses, not taking into account spatial overlapping (Prado et al, 2014;Mart ınez-Hern andez et al, 2015) but, instead, species composition. According to Prado et al (2014, p.3), 'the overlap and proximity of several CAs obtained with different grid sizes suggest consistent evidence that these regions exhibit a high degree of endemicity, with the presence of restricted and shared taxa'.…”

“…To identify congruence among the results, researchers have been employing two different approaches: (1) a comparison of the results obtained from different methods (Moline & Linder, 2006;Carine et al, 2009;DaSilva et al, 2015) or (2) the use of different sets of parameters under a particular method (e.g. Domingu ez et al, 2006;Casagranda, Roig-Juñent & Szumik, 2009;Prado et al, 2014). In either case, the number of resulting areas can be high and difficult to assess even under a consensus criterion.…”

“…In either case, the number of resulting areas can be high and difficult to assess even under a consensus criterion. Different approaches have been proposed to deal with high number of resulting areas, either through spatial overlap of AEs (Prado et al, 2014;Mart ınez-Hern andez et al, 2015) or by the use of combined quantitative criteria to choose AEs (DaSilva et al, 2015). As an alternative to employing different sets of parameters under a particular method, Ribeiro et al (2014) proposed a methodology for defining suitable values of grid size and the level of inclusiveness of consensus areas under objective criteria.…”

Rodents of the eastern and western slopes of the Tropical Andes: phylogenetic and taxonomic insights using DNA barcodes

“…The Andean rodent fauna is no exception to these environmental trends. Recent analyses have detected several hotspots of rodent diversity along the Andes, such as the eastern slopes in Ecuador and Peru (Prado et al 2015;Maestri and Patterson 2016).…”

Eficiência dos métodos de codificação em análises de endemismo: um exemplo do Oceano Atlântico Sul-Ocidental

“…Áreas de endemismo são as menores unidades de análise da biogeografia histórica e, como tal, são a base para construção de hipóteses sobre os processos responsáveis pela formação da biota de uma região (Morrone, 2001). Portanto, áreas de endemismo são hipóteses testáveis e modificáveis com a inclusão de novos dados de distribuição (Carvalho, 2011 (Aagesen, et al, 2009;Navarro, et al, 2009;Szumik et al, 2012;Prado et al, 2014;Martínez-Hernández et al, 2015;NogueraUrbano & Escalante, 2015).…”