Persistência do muriqui-do-norte, Brachyteles hypoxanthus, em fragmentos de Mata Atlântica

Abstract

Habitat loss of tropical forests causes fragmentation, decline, and isolation of species populations. This process has reduced the original cover of the Brazilian Atlantic Forest by almost 90% and, together with other factors, has allowed the northern muriqui (Brachyteles hypoxanthus) to become one of the most endangered primates in the world. We have been monitoring northern muriqui populations in the central highlands of the state of Espírito Santo (ES) since 2002. In addition to population and genetic studies, we have been studying landscape ecology, seeking to understand how isolated muriquis populations can survive in such a fragmented region. Our data indicate that the muriqui population consists of at least 120 individuals distributed in 13 forest fragments in the municipality of Santa Maria de Jetibá. Using landscape parameters and fragments with the presence of the species, we modeled which fragments would be appropriate for their persistence. We verified that the species is present only in part of the fragments considered adequate. In the present study, we intend to investigate if the presence/absence of the species is conditioned to the structure of fragments and landscape parameters. We used logistic regression and Mann-Whitney U test to compare parameters of fragments inhabited by muriquis with those considered “suitable” but not inhabited by muriquis. Our results showed that tree height and diameter, number of fallen/ dead trees, and surrounding initial forest cover are different in both groups of fragments and help explain their pattern of occurrence. The analyzed variables, even the non-significant ones, obtained values very similar to the values of the variables measured in other locations of occurrence of the species. This indicates great similarity between fragments not inhabited by muriquis and fragments inhabited by muriquis in Santa Maria de Jetibá and other locations.