Ecosystem services provided by black howler monkeys in human-modified habitats

Tropical forest loss and degradation from human activities drive large mammal declines, threatening ecosystems that depend on the natural services they provide. When tropical rainforest is transformed, primate species become threatened through disruptions to movement patterns, changes in resource availability, and negative impacts of human activities. Healthy primate populations support the correct functioning of tropical communities by providing essential ecosystem services, such as dispersing the seeds of the trees they feed on. To evaluate the effects of forest disturbance on primates and the long-term conservation outlook of a tropical ecosystem, I study wild black howler monkeys living in a protected forest and in an anthropogenic landscape in southeast Mexico. During my 10-week pilot study, generously funded by CLAS, I traveled to Chiapas, Mexico to meet with owners of forest fragments to request permission to conduct a study in their properties. My research team and I conducted preliminary disturbance surveys at each site. We aimed to select four forest fragments with at least one black howler monkey group to accompany the conserved primary forest of Palenque National Park and establish a gradient of human disturbance, from heavily disturbed to conserved. During the following eight weeks, we followed six black howler monkey groups, recording daily travel, individual and group behavior, feeding resources, defecation sites, and defecated seeds. Overall, we determined that a 1-yearlong study at each of the study sites will be feasible. We also tested data collection methods and field equipment, and we adjusted the research protocol accordingly if needed. With our study, we will evaluate the extent and efficacy of the ecosystem services provided by black howler monkeys in the anthropomorphic landscape. Our work has important implications for the conservation of black howler populations and the regeneration of their tropical rainforest habitat. Additionally, black howler monkey conservation has the potential to provide long-term financial and cultural benefits to local human communities.