Status of the muriqui (Brachyteles) populations remaining in the state of Rio de Janeiro, Brazil: Projeto Muriqui-Rio

Abstract

In his study of the status and geographic distribution of the muriqui, Brachyteles arachnoides, of the Atlantic forest, Aguirre (O mono Brachyteles arachnoides (É. Geoffroy). Situação atual da Espécie no Brasil, Acad. Brasil. Ciênc., Rio de Janeiro. 1971) documented its widespread disappearance from the state of Rio de Janeiro, identifying only six localities where it could still be found, and estimating a population of only 650 to 840 individuals. In this paper, I report on 25 survey expeditions carried out from 1999 to 2003 to verify the continued presence of muriquis in six localities in the state of Rio de Janeiro: the Serra dos Órgãos National Park, Desengano State Park, Paraíso Ecological Station, the Cairuçú Environmental Protection Area (adjoining the Serra da Bocaina National Park), the region of Macaé de Cima and the Itatiaia National Park. A total of 55 muriquis were seen in Serra dos Órgãos, Cairuçú, and Desengano. Local inhabitants reported that muriquis were now very rare in the region of Macaé de Cima and the Paraíso Ecological Station. No muriquis were seen in the Itatiaia National Park, but three specimens on show in the museum indicate that it is the northern muriqui (B. hypoxanthus) which occurs there, rather than the southern muriqui (B. arachnoides) known from the rest of the state.