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Aim: To predict the distribution of suitable environmental conditions (SEC) for eight African great ape taxa for a first time period, the 1990s and then project it to a second time period, the 2000s; to assess the relative importance of factors influencing SEC distribution and to estimate rates of SEC loss, isolation and fragmentation over the last two decades. Location: Twenty-two African great ape range countries. Methods: We extracted 15,051 presence localities collected between 1995 and 2010 from 68 different areas surveyed across the African ape range. We combined a maximum entropy algorithm and logistic regression to relate ape presence information to environmental and human impact variables from the 1990s with a resolution of 5 9 5 km across the entire ape range. We then made SEC projections for the 2000s using updated human impact variables. Results: Total SEC area was approximately 2,015,480 and 1,807,653 km2 in the 1990s and 2000s, respectively. Loss of predicted SEC appeared highest for Cross River gorillas (_59%), followed by eastern gorillas (_52%), western gorillas (_32%), bonobos (_29%), central chimpanzees (_17%) and western chimpanzees (_11%). SEC for Nigeria-Cameroon chimpanzees and eastern chimpanzees was not greatly reduced. Except for Cross River and eastern gorillas, the number of SEC patches did not change significantly, suggesting that SEC loss was caused mainly by patch size reduction. Main conclusions: The first continent-wide perspective of African ape SEC distribution shows dramatic declines in recent years. The model has clear limitations for use at small geographic scales, given the quality of available data and the coarse resolution of predictions. However, at the large scale it has potential for informing international policymaking, mitigation of resource extraction and infrastructure development, as well as for spatial prioritization of conservation effort and evaluating conservation effectiveness.

In order to assess the impact of human activities on chimpanzee behavior, we compared reactions to humans of Eastern chimpanzees (Pan troglodytes schweinfurthii) living in proximity to and at a distance from roads and settlements in the Bili-Uele landscape in Northern Democratic Republic of the Congo (DRC). We found that chimpanzees in the remote Gangu Forest were more likely to show curious or neutral reactions to us and were less likely to flee than those living closer to roads. In addition, arboreal contact durations with Gangu chimpanzees lasted significantly longer than elsewhere. The most likely explanation for this phenomenon is that with increasing distance from roads, chimpanzees have in the recent past had fewer negative encounters with humans, and thus never learned to fear them. The discovery of this population of naive chimpanzees presents us with an important research and conservation opportunity that may result in the installation of a long-term research site and increased protection of the population.

A network of resource management areas (RMAs) exists across tropical Africa to protect natural resources. However, many are poorly managed and weakly protected. We evaluated how the lack of conservation effort influences the extinction risk of African great apes. We compiled information on presence/absence of primary (law enforcement guards) and secondary (tourism, research) conservation activities and nongovernmental conservation organizations (NGOs) support for 109 RMAs over the last 20 years. Along with these data, we collected environmental and anthropogenic variables, including recent records of ape presence/absence for all RMAs. As expected, law enforcement as a primary activity was the best predictor of ape survival rather than tourism or research as secondary activities. Furthermore, long-term NGO support had a significant positive influence on ape persistence. Our study demonstrates the feasibility of evaluating the relative importance of different conservation activities, an important step towards more evidence-based approaches in ape conservation.