Preliminary assessment of the impacts of human activities on gorillas Gorilla gorilla gorilla and other wildlife at Dzanga-Sangha Reserve, Central African Republic



The aim of this study was to make preliminary assessments of the effects of human activities on the gorillas and other wildlife in the Dzanga-Ndoki Park and broader Dzanga-Sangha Dense Forest Reserve (RDS), Central African Republic. During a month-long survey in 1997, observation and sign of humans and large mammals, including ape nest-sites, were recorded on 81.2 km of line transects in three sectors of the park and reserve. Human activities, including intensities of logging and hunting, appeared to decrease with distance from the population centres and were lower in the park than in the reserve sectors. Encounter rates with sign of duikers Cephalophus spp., monkeys Cercopithecus spp. and Cercocebus albigena, elephants Loxodonta africana, and gorillas Gorilla gorilla gorilla were generally lower in regions of high human activity in the reserve than in the park sectors. Nevertheless, gorilla nest-site densities did not vary significantly between sectors or with human activity levels. A high frequency of zero (bare ground) nests at RDS suggests that gorilla surveys that rely on line transect methods and use nest decomposition rates from other studies may sometimes underestimate gorilla densities. This study suggests that current levels of exploitation in managed hunting zones of national forest reserves may be negatively affecting targeted wildlife populations in these zones. Assessments should be a regular part of efforts to monitor the health of wildlife populations in managed protected zones. Participation by Central Africans in research will continue to benefit conservation and development efforts.