Diversidade de mamíferos do baixo Rio Jufari, Roraima, Brasil

Faunal inventories are essential to directly access the diversity of a region. Although the Amazon rainforest exhibit large estimates of mammal species richness, the region still exhibits large sampling gaps. Aiming to fill a sampling gap on the mammalian diversity in the Brazilian Amazon rainforest, we conducted an inventory of non-volant mammals at “terra firme” forest near the mouth of Rio Jufari, an affluent of north bank of Rio Negro, near its confluence with Rio Branco. The total effort of live traps were 3.673 traps/ night, the total effort of pitfall traps were 2.700 traps/ night, and lastly, for large mammals we performed unstandardized line transect census, occasional meetings and material donated by Caicubi community members. The pitfall traps proved to be extremely valuable for the small non-volant mammal sampling. We observed a small mammalian diversity, when compared to other inventories throughout the Amazon basin. We recorded 27 species belonging to 25 genera, 16 families and nine orders of Class Mammalia. The most parts of recorded species were known from Guyana area. However, we recorded an extension of distribution for Marmosops bishopi and taxonomic comments about the marsupial Monodelphis brevicaudata, and about the arboreal rodent genera Oecomys (species with few records in Brazil and first time recorded to Rio Negro - Rio Brance confluence) and Makalata (genus with few collected specimens deposited in Brazilian natural collections). It is remarkable the extremely low number of species of the order Primates. Interviewed data suggested that this few number of primates specimens was historical, and areas closer to Rio Negro and Rio Branco showed a higher diversity. Our samples showed that Rio Negro – Rio Branco confluence do not presented exclusive fauna, once the region share its mammal diversity with other confluence areas in the Amazon basin, mainly on its northeastern region.