Conservation Challenges Facing Two Threatened Endemic Titi Monkeys in a Naturally Fragmented Bolivian Forest

The south-western Beni forest-grassland mosaic in central western Bolivia, a natural fragmented forest area, is home to two Bolivian primate endemics: the Beni titi monkey (Callicebus modestus) and the Olalla brothers titi monkey (Callicebus olallae). Despite extremely low sample sizes (n = 1 and n = 2, respectively), these species have been consistently recognized in taxonomic reviews of the genus since their discovery and description in the late 1930s; however, no new field data was available until 2002. In this chapter, we present a summary of our efforts to: describe the distributional limits of both species, determine their phenotypical characteristics in the field, conduct preliminary analyses of genetic differences between the two species, estimate population densities, describe the composition and structure of the naturally fragmented forest habitats where they occur, and document the behavioral ecology of both species. We also report the threats facing these two range restricted endemics through informal questionnaires with local actors and deforestation studies. Additionally, we detail efforts to conserve these species to date, such as local outreach campaigns, coordination with national government offices, and assistance to local municipalities for inclusion of these species requirements in municipal development plans and their prominence in the justification for the creation of a Municipal Protected Area in the Santa Rosa municipality. Finally, we identify priority conservation actions for the future.