Association of the "IUCN vulnerable "spiny rat Clyomys bishopi (Rodentia:Echimyidae)with palm trees and armadillo burrows in southeastern Brazil

The globally vulnerable Clyomys bishopi ,a semi-fossorial and colonial rodent,is apparently limited to cerrado (savannah-like vegetation)physiognomies in São Paulo State,Brazil.The aim of the study was to verify whether the presence of C.bishopi is associated to the occurrence of palm trees (Attalea gearensis, Syagrus loefgrenii )and armadillo burrows.Thirty six quadrats were placed in different physiognomies of cerrado vegetation at Itirapina Ecological Station,southeastern Brazil to survey the number of C.bishopi burrows of individuals of palm trees and burrows of armadillos.There was a strong dependence and association between the number of C.bishopi burrows and all measured variables (Contingency tables and Spearman rank correlations).It is suggested that this rodent can be found in great numbers where palm trees are abundant.The use of armadillo burrows possibly makes the movement of the rodents easier inside their own galleries.Rev.Biol. Trop. 52(4):1009-1011.Epub 2005 Jun 24.El roedor colonial Clyomys bishopi está aparentemente limitado a vegetación de semi-sabana (cerrado)en el estado de São Paulo,Brasil.El objetivo de este estudio fue verificar si la presencia de C.bishopi está asociada a la individuos de las palmeras Attalea gearensis,Syagrus loefgrenii y madrigueras de armadillos.El estudio fue realizado en la Estación Ecológica de Itirapina,en el sureste de Brasil.Treinta y seis cuadrantes fueron dispuestos en diferentes fisionomías del la vegetación del cerrado para encuestar el número de madrigueras de C.bishopi, árboles individuales de palma y madrigueras de armadillos.Se calcularon tablas de contingencia y correlaciones de Sperman para evaluar, respectivamente, la dependencia y asociación entre el número de madrigueras de C.bishopi y las otras variables.Se encontró una fuerte dependencia y asociación entre el número de madrigueras de C.bishopi y todas las variables medidas.Esto sugiere que este roedor alcanza grandes poblaciones cuando hay palmeras en abundancia. El uso de madrigueras de armadillos posiblemente facilita el movimiento de los roedores dentro de sus propias galerías

The Biogeographic Network of Birds in the Brazilian Cerrado May Guide Conservation Efforts

The Brazilian Cerrado, characterized by grasslands, savannahs and riverine forests, is a biodiversity hotspot, threatened by the expansion of the agricultural frontier, and therefore, needs effective conservation actions. At the national level, the Cerrado core-region has received more conservation efforts than the marginal (non-core) areas, being considered more biodiverse. However, many marginal areas are also home to high species richness and endemism. Birds represent a highly diverse and widely distributed biological group, whose variety of functions gives them important roles in the maintenance of ecosystem services. In this study the authors analysed the distribution patterns of bird biodiversity in the Brazilian Cerrado and verified whether a separation into core and marginal Cerrado zones would make sense for birds’ distribution, as this is an important issue concerning resources allocation for biodiversity conservation. The authors developed a biogeographic network analysis considering 42 sites with savannah vegetation distributed throughout the country and built two presence-absence matrices for birds – with and without species typical of the woodland Cerrado and forest physiognomies – and generated two biogeographic networks. The network without woodland/forest bird species showed no modularity, whereas the complete network produced three modules: Northwest, Centre-South and Centre-North. Network modularity was mainly determined by forest/woodland bird species. The Northwest region was richer and had a greater number of regional species compared to the other two modules; lower richness of bird species was found in the Centre-South region, which had more widespread species. The biogeographic pattern for the Cerrado birds perceived in this study did not evidence a clear dichotomy between core versus marginal regions. Therefore, the same conservation effort should be implemented throughout the Cerrado