Primates as Umbrella Taxa for Biodiversity Conservation On Bioko Island, Equatorial Guinea

Bioko Island, Equatorial Guinea is one of the most important places in Africa for primate conservation, but numerous factors including a cultural preference for bushmeat and a lack of effective law enforcement have contributed to widespread bushmeat hunting, threatening the survival of the island’s larger-bodied vertebrates. Using bushmeat market data collected over 13 years in the market of the capital, Malabo, we recorded over 41,000 primate carcasses, documenting 'mardi gras' consumption patterns, seasonal carcass availability, and government interventions contributing to increased offtake levels. Forest surveys were also conducted throughout Bioko’s two protected areas in order to quantify primate populations and hunting pressure. Using these data, we were able to document the significant negative impact bushmeat hunting had on monkey populations, estimate the differential vulnerability of each monkey species, and develop ecological niche models to approximate the distribution of each of Bioko’s monkey species. The critically endangered Pennant’s red colobus (Procolobus pennantii), for example, was the most vulnerable to hunting pressure and appears to have been extirpated throughout Bioko, including Pico Basilé National Park, except for an area of less than 250 km² in the southwest of the Gran Caldera Scientific Reserve (GCSR). These results have allowed for the identification of primate hotspots, and thus, priority areas for conservation on Bioko, leading to comprehensive recommendations that could greatly improve the status of overall biodiversity conservation on Bioko. For example, effective implementation of the prioritization scheme we derived would protect not only the core populations of all seven monkey species, but also the critical nesting habitat of four species of marine turtles, monsoon forest habitat (among the wettest in the world), and unique afromotane formations at higher elevations. These recommendations form the framework of current collaborative efforts which are bridging the gap between investigators and legislators in order to develop and effectively implement a management plan for the Gran Caldera Scientific Reserve, and to achieve UNESCO Biosphere Reserve status for the entire island of Bioko. By synthesizing these multidisciplinary data into a suite of concrete data-driven recommendations, we have been able to help ‘kickstart’ conservation progress on Bioko at a critical time for its wildlife, as well its people, and in doing so, there may yet be a positive future for the biodiversity of Bioko.