Joshua M. Linder

Protected Areas in Tropical Africa: Assessing Threats and Conservation Activities

Numerous protected areas (PAs) have been created in Africa to safeguard wildlife and other natural resources. However, significant threats from anthropogenic activities and decline of wildlife populations persist, while conservation efforts in most PAs are still minimal. We assessed the impact level of the most common threats to wildlife within PAs in tropical Africa and the relationship of conservation activities with threat impact level. We collated data on 98 PAs with tropical forest cover from 15 countries across West, Central and East Africa. For this, we assembled information about local threats as well as conservation activities from published and unpublished literature, and questionnaires sent to long-term field workers. We constructed general linear models to test the significance of specific conservation activities in relation to the threat impact level. Subsistence and commercial hunting were identified as the most common direct threats to wildlife and found to be most prevalent in West and Central Africa. Agriculture and logging represented the most common indirect threats, and were most prevalent in West Africa. We found that the long-term presence of conservation activities (such as law enforcement, research and tourism) was associated with lower threat impact levels. Our results highlight deficiencies in the management effectiveness of several PAs across tropical Africa, and conclude that PA management should invest more into conservation activities with long-term duration.

Long-term urban market dynamics reveal increased bushmeat carcass volume despite economic growth and proactive environmental legislation on Bioko Island, Equatorial Guinea

Bushmeat hunting is extensive in west and central Africa as both a means for subsistence and for commercial gain. Commercial hunting represents one of the primary threats to wildlife in the region, and confounding factors have made it challenging to examine how external factors influence the commercial bushmeat trade. Bioko Island, Equatorial Guinea is a small island with large tracts of intact forest that support sizeable populations of commercially valuable vertebrates, especially endemic primates. The island also has a low human population and has experienced dramatic economic growth and rapid development since the mid-1990’s. From October 1997 – September 2010, we monitored the largest bushmeat market on Bioko in Malabo, recording over 197,000 carcasses for sale. We used these data to analyze the dynamics of the market in relation to political events, environmental legislation, and rapid economic growth. Our findings suggest that bushmeat hunting and availability increased in parallel with the growth of Equatorial Guinea’s GDP and disposable income of its citizens. During this 13-year study, the predominant mode of capture shifted from trapping to shotguns. Consequently, carcass volume and rates of taxa typically captured with shotguns increased significantly, most notably including intensified hunting of Biokos unique and endangered monkey fauna. Attempts to limit bushmeat sales, including a 2007 ban on primate hunting and trade, were only transiently effective. The hunting ban was not enforced, and was quickly followed by a marked increase in bushmeat hunting compared to hunting rates prior to the ban. Our results emphasize the negative impact that rapid development and unenforced legislation have had on Bioko’s wildlife, and demonstrate the need for strong governmental support if conservation strategies are to be successful at preventing extinctions of tropical wildlife.

Model selection, zero-inflated models, and predictors of primate abundance in Korup National Park, Cameroon.

Determining the ecological and anthropogenic factors that shape the abundance and distribution of wild primates is a critical component of primate conservation research. Such research is complicated, however, whenever the species under study are encountered infrequently, a characteristic of many taxa that are threatened with extinction. Typically, the resulting data sets based on surveys of such species will have a high frequency of zero counts which makes it difficult to determine the predictor variables that are associated with species abundance. In this study, we test various statistical models using survey data that was gathered on seven species of primate in Korup National Park, Cameroon. Predictor variables include hunting signs and aspects of habitat structure and floristic composition. Our statistical models include zero-inflated models that are tailored to deal with a high frequency of zero counts. First, using exploratory data analysis we found the most informative set of models as ranked by Δ-AIC (Akaikes information criterion). On the basis of this analysis, we used five predictor variables to construct several regression models including Poisson, zero-inflated Poisson, negative binomial, and zero-inflated negative binomial. Total basal area of all trees, density of secondary tree species, hunting signs, and mean basal area of all trees were significant predictors of abundance in the zero-inflated models. We discuss the statistical logic behind zero-inflated models and provide an interpretation of parameter estimates. We recommend that researchers explore a variety of models when determining the factors that correlate with primate abundance.

The Threat of Industrial Oil Palm Expansion to Primates and Their Habitats

Large-scale, industrial oil palm (Elaeis guineensis Jacq.) plantations are rapidly expanding in tropical forest regions to supply a growing global demand for palm oil, the world’s most popular vegetable oil. Such agro-industrial enterprises are a growing threat to primates and their habitats. We review the history of palm oil production, starting with its origins in Africa followed by its expansion to other tropical regions including Malaysia and Indonesia, where over 85 % of the world’s palm oil is now produced. We examine the ecological and socioeconomic impacts of industrial oil palm developments and address global attempts to produce palm oil sustainably. Our analysis indicates that large-scale, industrial oil palm plantations directly destroy tropical forest biodiversity and negatively affect adjacent intact forests. Contrary to arguments made by many advocates of industrially produced palm oil, we find that such production schemes may not be in the economic interests of local communities and may lead to social conflict. We find that in many cases industrial oil palm developments suffer from lack of transparency and fail to obtain the free, prior, and informed consent of local people who are at a great disadvantage when negotiating with agribusinesses. We present evidence indicating that efforts to produce palm oil sustainably through the Roundtable on Sustainable Palm Oil suffer from lack of oversight, enforcement, and accountability and, ultimately, allow for deforestation. We recommend ways to reduce the ecological and social impacts of industrially produced palm oil and suggest that the conservation, development, and human rights communities work with national governments to develop alternative palm oil production schemes that reduce environmental impacts and socioeconomic risks.