Road expansion and associated increases in hunting pressure are a rapidly growing threat to African tropical wildlife. In the rainforests of southern Gabon, we compared abundances of larger (>1 kg) mammal species at varying distances from forest roads and between hunted and unhunted treatments (com-paring

Aim Human activities are major determinants of forest elephant ( Loxodonta africana cyclotis ) distribution in Gabon, but the types and intensity of disturbance that elephants can tolerate are not known. We conducted dung surveys within the Gamba Complex of Protected Areas in SW Gabon to examine (1) the feasibility of noninvasive faecal analyses for monitoring stress physiology, and (2) the influence of petroleum operations on stress levels in forest elephants.Location Gabon, Central Africa. MethodsWe identified multiple dung piles from the same individual by matching their eight-locus microsatellite genotypes, and measured faecal concentrations of glucocorticoid metabolites as an indicator of stress in areas subject to different levels of disturbance: (1) Loango National Park (2) an 'industrial corridor' dominated by oil fields, and (3) a nearby area of human settlements. ResultsWe obtained unique microsatellite genotypes and faecal glucocorticoid metabolite (FGM) concentrations for 150 forest elephant individuals, which is the largest hormonal data set for wild African forest elephants to date. Adults exhibited higher mean FGM concentrations than juveniles, and in contradiction of our expectations of chronic stress around oil fields, elephants in Loango National Park exhibited significantly higher FGM concentrations than elephants in the industrial corridor. Main conclusionsWe argue that forest elephants in the industrial corridor of the Gamba Complex have become acclimated to oil fields, resulting in part from oil company regulations that minimize stressful interactions between elephants and petroleum operations. Our findings for a flagship species with substantial ecological requirements bode well for other taxa, but additional studies are needed to determine whether oil operations are compatible over their life span with rain forest ecosystems in Central Africa.

Many animals can adjust their behavioral strategies to reduce predation risk. We investigated whether rain forest monkeys and duikers alter their antipredatory behavior in response to hunting by humans in southwestern Gabon. We compared monkey and duiker responses to human observers in an area where hunting is prohibited, to those in a nearby area where hunting pressure is moderate but spatially variable. The results of our study indicate that monkeys become more secretive when hunted, commencing alarm calls only when at a certain distance (typically > 50 m) from humans. We found no difference in monkey group size between hunted and no-hunting areas. In no-hunting areas, duikers often freeze in response to approaching observers, but in hunted areas they abandon this strategy and rapidly flee from humans. Duikers also whistle more often in areas where they are hunted frequently. Our findings have at least two important implications. First, behavioral observations of monkeys and duikers may be useful in gauging local hunting intensity in African rain forests. Second, duiker densities are likely to be overestimated in hunted areas, where they more readily flee and whistle, and underestimated in no-hunting areas, where they rely on freezing behavior to avoid detection. Because behavioral adaptations to hunting vary both among species and localities, these differences should be considered when attempting to derive population-density estimates for forest wildlife.Abstract in Spanish is available at http://www.blackwell-synergy.com/loi/btp.

We investigated the patterns of genetic diversity and structure of African forest elephants in a human-modified landscape in the Gamba complex of protected areas (GCPA), a tropical wilderness area along the southwest coast of Gabon. We collected 298 elephant fecal samples from four sites (Sette Cama, Gamba area, Vera Plains, and Mayonami), along approximately 80 km of coastline from north to south. We used microsatellites and mitochondrial DNA (mtDNA) to successfully genotype 295 of the 298 fecal samples, and identified 213 individuals. Using sex markers, we identified 84 males and 118 females; we could not determine the sex of the remaining 11 individuals. We also characterized the sex, group size, and social status of crop-raiding elephants and did not find characteristics distinguishing them from nonraiders. Overall, our mtDNA and microsatellite markers revealed that elephants in the research area maintain high levels of genetic variation and low levels of subdivision. Gene flow appears to be mostly mediated by male dispersal away from natal herds. Our structure analysis revealed two highly admixed genetic clusters, attributable to high connectivity among the protected areas. However, forest areas within the GCPA have become increasingly fragmented by human-induced habitat modification. We detected a pattern of isolation by distance, accentuated by the presence of the town of Gamba between Sette-Cama and Mayonami. We found a high degree of connectivity among sampling locations within the GCPA. This supports the importance of establishing agricultural best practices to reduce habitat loss that may sever gene exchange and to maintain connectivity, as well as to avoid human-elephant conflict that can result in retaliatory killing of elephants in this area. This study emphasizes the importance of conducting baseline monitoring of demographic data, genetic diversity, and structure to enable future comparisons to assess the long-term impact of human-induced habitat fragmentation. K E Y W O R D Scrop raids, forest elephant, genetics, land cover change