Deforestation and Primate Habitat Availability in Los Tuxtlas Biosphere Reserve, Mexico

Los Tuxtlas Biosphere Reserve (LTBR) in southeast Mexico is characterized by high rates of deforestation and habitat deterioration, containing two Mexican primate species, Alouatta palliata and Ateles geoffroyi. In this study, we integrate the analysis of landscape dynamics with primate population research covering a period of 21 years (1986-2007), assessing the impacts of habitat transformation on primate populations in a study area located in the southeast region of the LTBR. We found the higher deforestation rate (1.5%) from 1986 to 2000, compared to 2000-2007 (0.5%), but reduction in primate’s habitat was of 62% from 1986-2007. Land cover changes have modified the landscape in such a way that current available habitat for primates is constituted by small forest patches, immersed in a pasture matrix. A total of 37 A. palliata and 68 A. geoffroyi individuals were counted; these data were compared with information available for the same primate populations in 1987 and 2000, revealing that despite habitat loss, primate population sizes have remained relatively stable. The analysis of occupation and colonization of forests fragments by primates suggests that fragment size and connectivity are key landscape features for the persistence of primates in the region. Our results imply that strong anthropogenic pressure against primate habitat is still taking place in this portion of LTBR; and that habitat availability, as well as primate population viability in this region, are linked to political and socioeconomic factors affecting land use and production systems adopted by locals, as well as to the management efforts of the LTBR.