Title
Comparing ape densities and habitats in northern Congo: Surveys of sympatric gorillas and chimpanzees in the Odzala and Ndoki Regions
Author(s)
Devos C., Sanz C., Morgan D., Onononga J.-R., Laporte N., Huynen M.-C.
Published
2008
Publisher
American Journal of Primatology
Published Version DOI
https://doi.org/10.1002/ajp.20514
Abstract
The conservation status of western lowland gorillas and central chimpanzees in western equatorial Africa remains largely speculative because many remote areas have never been surveyed and the impact of emergent diseases in the region has not been well documented. In this study, we compared ape densities and habitats in the Lokoué study area in Odzala National Park and the Goualougo Triangle in Nouabalé-Ndoki National Park in northern Republic of Congo. Both of these sites have long been considered strongholds for the conservation of chimpanzees and gorillas, but supposedly differ in vegetative composition and relative ape abundance. We compared habitats between these sites using conventional ground surveys and classified Landsat-7 ETM+ satellite images. We present density estimates via both standing-crop and marked-nest methods for the first time for sympatric apes of the Congo Basin. The marked-nest method was effective in depicting chimpanzee densities, but underestimated gorilla densities at both sites. Marked-nest surveys also revealed a dramatic decline in the ape population of Lokoué which coincided with a local Ebola epidemic. Normal baseline fluctuations in ape nest encounter rates during the repeated passages of marked-nest surveys were clearly distinguishable from a 80% decline in ape nest encounter rates at Lokoué. Our results showed that ape densities, habitat composition, and population dynamics differed between these populations in northern Congo. We emphasize the importance of intensifying monitoring efforts and further refinement of ape survey methods, as our results indicated that even the largest remaining ape populations in intact and protected forests are susceptible to sudden and dramatic declines. © 2008 Wiley-Liss, Inc.
Keywords
comparative study; conservation status; demographic survey; hominid; national park; population density; population estimation; sympatry; Africa; Central Africa; Congo; Goualougo Triangle; Nouabale-Ndoki National Park; Odzala National Park; Sub-Saharan Africa; Gorilla gorilla; Gorilla gorilla gorilla; Pan; Pan troglodytes

Access Full Text

A full-text copy of this article may be available. Please email the WCS Library to request.



Back

PUB12021