The state of Rio de Janeiro is located in a region that can be considered biogeographically important for harboring extreme geographical limits of the Serra do Mar and lowland forests, which are very significant for the distribution of several bird species. In this study, through extensive bibliographic search, 59 bird species were found with their southern (40 species) or northern (19 species) limit of distribution located in the state of Rio de Janeiro. Birds with the southern limit of distribution in Rio de Janeiro have been recorded in almost the entire state, except in the upper valley of the Paraíba do Sul river and the western portion of the coastal zone of the state. This birds species are predominantly associated with lowland and submontane forests and more than half is included in the list of species threatened with extinction in the state. Birds with the northern limit of distribution in the state of Rio de Janeiro can be classified into two basic groups according to their distribution pattern in the region. The first group consists of endemic montane Atlantic forest birds, while the second group consists of occasional visitors associated with aquatic environments. The low proportion of threatened bird species among those with the northern limit of distribution in Rio de Janeiro can be explained by the high proportion of species inhabiting montane forests, which are more protected than the lowland forests.
Atlantic Forest; Biogeography; geographical distribution; Serra do Mar; southeastern Brazil
