Knowledge about mammals of the Atlantic Forest is still lacking, especially because some places remain poorly studied or inventoried, which makes conservation initiatives difficult. We aimed to determine the species richness and composition of medium and large sized mammals in a semideciduous forest remnant, Morro do Coco, thus contributing information about the occurrence of mammalian fauna in the metropolitan region of Porto Alegre, southern Brazil. The methods consisted of interviews with local inhabitants, visual records and sand plot analysis. The study took place from July 2008 to April 2009, with monthly expeditions of three days. Sixteen species of mammals were recorded, seven of which are threatened with extinction in Rio Grande do Sul and one nationally. The predominant trophic group was the frugivorous/herbivorous. The study area is situated in a prioritized zone for the conservation of mammals in Greater Porto Alegre, since it consists of one of the last remnants where the phytophysionomies that originally occupied the edge of Guaiba Lake and granite hills of the region are represented and preserved.

Neste estudo, avaliou-se a diversidade, riqueza e a composição das espécies de morcegos no dossel e subbosque de um remanescente de Mata Atlântica no Sul do Brasil, no município de Porto Alegre, Rio Grande do Sul. Entre julho de 2010 e junho de 2011, morcegos foram capturados por meio de 10 redes de neblina, cinco no dossel e cinco no sub-bosque. Foram calculados o índice de Diversidade de Shannon-Wiener (H'), a riqueza esperada (Chao 1 e Jackknife 2) e o índice de constância das espécies para a área como um todo. Aplicou-se o teste Exato de Fisher para verificar se as capturas foram diferentes no dossel e o sub-bosque. Capturaram-se 107 espécimes de quirópteros, 20 indivíduos de cinco espécies no dossel e 87 indivíduos de sete espécies no sub-bosque. O índice de diversidade foi de 1.481e a riqueza esperada de nove (Chao 1) e 10 (Jackknife 2). O índice de constância revelou que Sturnira lilium e Glossophaga soricina são relativamente comuns na área de estudo. A riqueza registrada representa cerca de 22% das espécies de morcegos listada para o Rio Grande do Sul. A análise de estratificação vertical demonstrou que algumas espécies são mais frequentes no dossel e outras no sub-bosque.

Reduction in the size and loss of the quality of habitats are considered the greatest threats to bat species. Aiming to complement information, the objective of this study was to evaluate, from compiled data, the influence of the size of forest fragments and their degree of conservation on the richness and composition of chiropteran fauna in the Atlantic rain forest. A total of 33 publications on Chiroptera in the Atlanticrain forest was reviewed and a list of 86 species was extracted from them. The size of forest fragments exhibited positive and significant relationship with the total number of Relatively Common Species, Rare Species, Not Generalist species and with richness. Positive and significant relationship was observed between degree of conservation of the forest fragments and the total number of Rare Species, of Not Generalist species and with richness. The results here presented indicate that largeand well-conserved fragments of Atlantic rain forest should be the priority when the intention is to maintain a high richness of Chiroptera and of Rare Species and Not Generalist Species.

Reduction in the size and loss of the quality of habitats are considered the greatest threats to bat species. Aiming to complement information, the objective of this study was to evaluate, from compiled data, the influence of the size of forest fragments and their degree of conservation on the richness and composition of chiropteran fauna in the Atlantic rain forest. A total of 33 publications on Chiroptera in the Atlantic rain forest was reviewed and a list of 86 species was extracted from them. The size of forest fragments exhibited positive and significant relationship with the total number of Relatively Common Species, Rare Species, Not Generalist species and with richness. Positive and significant relationship was observed between degree of conservation of the forest fragments and the total number of Rare Species, of Not Generalist species and with richness. The results here presented indicate that large and well-conserved fragments of Atlantic rain forest should be the priority when the intention is to maintain a high richness of Chiroptera and of Rare Species and Not Generalist Species.