Diversity and habitat preference of medium and large-sized mammals in an urban forest fragment of southwestern Amazon

We assessed the species composition and abundance of medium and large-sized mammals in an urban forest fragment in the Brazilian Amazon, and recorded the preference of some species for particular phytophysiognomies. We placed nine transects with 20 sand plots each in three phytophysiognomies: open rainforest with a dominance of bamboos (OFB), open rainforest with palm trees (OFP), and dense rainforest (DF). We calculated species abundance as the number of records/plot.day, in a total of 2,700 plots.day. We recorded twelve mammal species; Sylvilagus brasiliensis (Linnaeus, 1758) and Dasyprocta fuliginosa (Wagler, 1831) were the most abundant. The results differed among phytophysiognomies: DF presented the highest mammal diversity, whereas the species composition of OFP was less similar than that of other phytophysiognomies. Rodents showed higher preference for OFP and Sylvilagus brasiliensis was more abundant in OFB. The study area showed high species richness, with the occurrence of mesopredators, but there was a predominance of common species adaptable to disturbed environments, which reflects the severe isolation degree of the forest fragment and the hunting pressure that is still present.Original Abstract: Nos avaliamos a composicao e abundancia de mamiferos de medio e grande porte em um fragmento florestal urbano na Amazonia brasileira, alem de registrar a preferencia de habitat de algumas especies a determinadas fitofisionomias. Nove transectos com 20 parcelas de areia cada foram dispostas de forma igualitaria em tres fitofisionomias: Floresta Ombrofila Aberta com Bambu Dominante (FAB), Floresta Ombrofila Aberta com Palmeira (FAP) e Floresta Ombrofila Densa (FD). A abundancia das especies foi obtida pelo numero de registros da especie/parcelas.dia, totalizando 2700 parcelas.dia. Doze especies de mamiferos foram registradas, sendo Sylvilagus brasiliensis (Linnaeus, 1758) e Dasyprocta fuliginosa (Wagler, 1831) as mais abundantes. Nossos resultados apresentaram diferenciacao em termos de especies para as fitofisionomias: a FD apresentou maior diversidade de mamiferos, enquanto a composicao de especies da FAP apresentou maior dissimilaridade com relacao as demais. Os roedores tiveram maior preferencia pela FAP e Sylvilagus brasiliensis apresentou maior abundancia na FAB. A area apresentou riqueza de especies relevante, com a ocorrencia de mesopredadores, mas ha o predominio de especies comuns e adaptaveis a ambientes perturbados, refletindo o acentuado gr