Can landscape and species characteristics predict primate presence in forest fragments in the Brazilian Amazon?

Habitat loss and fragmentation are global conservation concerns, but animal species do not respond to these threats in the same manner. At the Biological Dynamics of Forest Fragments Project (BDFFP), located 80 km north of Manaus, Amazonas, Brazil, the distribution and persistence of six native primate species differ among fragments that were isolated in 1980s. We identified both landscape and species characteristics predicting the presence of primates in these forest fragments. Fragment size positively and distance to nearest forested area negatively predicted primate species richness in the fragments; however, these relationships were not straightforward because these two variables were correlated. The proportion of fruit in a species' diet was the most important factor predicting its presence in the forest fragments, with species relying primarily on frugivory faring poorly. Home range size was the second-best predictor of a species' presence; however, some species with large home ranges were present in the 10-ha forest fragments. The extent to which the individual primate species traveled in and out of the fragments varied, suggesting that further research is necessary to determine the primary factors that lead to the animals' use of the matrix. We conclude that in addition to conserving large tracts of habitat, reducing the isolation of the forest fragments through the creation of forest corridors and through the presence of additional forest fragments within the agricultural matrix may increase animal movement across the landscape. Such changes to the matrix may be critical for those species that do not readily traverse non-forested areas.