Efeitos da fragmentação insular sobre a comunidade de primatas na Amazônia Central

Abstract

The construction of hydroelectric dams is today an important cause of the loss of habitat in the Amazon Region and many other of these enterprises are in governmental planning to be constructed. With the filling of the reservoirs, extensive areas of forests are flooded, causing a drastic alteration of the original landscape. The Balbina dam, the area where the present study has been conducted had 2,360 km2 of flooded forest that were transformed into a lake and more of 3,500 islands in which the effect of isolation on its biodiversity is practically unknown. To carry out the present study we selected twenty islands of different sizes (0-2000 ha) to verify how the primate community have been affected at local scale (habitat structure) and regional scale (landscape configuration). 240 km were covered using line-transect method and 1335 km were censused by boat. Data on five forest structure components were collected and related with the primate community. Seven species of primates were found, which Alouatta macconelli (n=17) and Saimiri sciureus (n=5) were registered in more and less islands, respectively. We observed that island complexity affected the primate community at local scale, whereas area and proximity determined the structure of community at regional scale. Our results highlight that patch size of at least 100 ha and with low isolation are important to maintenance the primate diversity and have to be prioritized in conservation actions on hydroelectrics.