Chimpanzees surviving in a fragmented high‐altitude forest landscape of the Congolese Albertine Rift

Anne Laudisoit,Jacob Willie,Samantha Maher,Tiffany Scholier,Joseph Omatoko,Bienvenu Ndjoku,Pierre Huyghe,Pascal Baelo,Jérôme Dz'Na,Thurston Cleveland Hicks,Gustave Ndjango Ngbathe,Justin Asimonyio Anio,Erik Verheyen,Tara Hoda,Oti Kpanyogo,Nikki Tagg,Guy Crispin Gembu,Claude Mande,Herwig Leirs

doi:10.1111/csp2.403

Abstract

AbstractThis paper documents a community of eastern chimpanzees (Pan troglodytes schweinfurthii Giglioli, 1872) inhabiting three relict forest fragments situated on the Lake Albert escarpment, down the Ituri highlands, of eastern Democratic Republic of the Congo (DRC). The area explored had a combined forested surface of ±18.15 km2 in 2017, shrinking by 1.2% per year between 2010 and 2015. Between 2015 and 2017, we found 160 chimpanzee nests along 37.6 km of pilot walks, some up to 2,000 m altitude. Another 123 nests logged along 6.7 km transects led to an estimate of chimpanzee density of 4.62 weaned individuals per square kilometer of forest habitat. Camera‐trap images and direct observations revealed that this community is comprised of a minimum of 42 weaned individuals, which translates into an estimated density of 2.3 chimpanzees per square kilometer. The increasing rate of forest degradation threatens to erode the cultural and genetic diversity of nonhuman primates in eastern DRC; the local people however exhibit willingness to establish a community managed reserve. We hope that this report will lead to the recognition of this site as a Chimpanzee Conservation Unit, facilitating further research in these “Relict Altitude Forests Fragments of the Albert Lake Escarpment” (or RAFALE landscape) and the Ituri highlands where other undocumented chimpanzee communities occur.

Highlights

Due to its relative isolation from other East African mountain ecosystems, the Albertine Rift has been recognized as a biodiversity hotspot (Plumptre et al, 2007)
About two-thirds of the Albertine Rift is situated in eastern Democratic Republic of the Congo (DRC)
The DRC hosts at least 49 species of primates (IUCN, 2020), but in some areas their populations are fragmented and in decline (Hicks et al, 2010). This is the case for the eastern chimpanzee Pan troglodytes schweinfurthii, which is threatened throughout their range (Hicks et al, 2010)

Summary

| INTRODUCTION

Due to its relative isolation from other East African mountain ecosystems, the Albertine Rift has been recognized as a biodiversity hotspot (Plumptre et al, 2007). The DRC hosts at least 49 species of primates (IUCN, 2020), but in some areas their populations are fragmented and in decline (Hicks et al, 2010) This is the case for the eastern chimpanzee Pan troglodytes schweinfurthii, which is threatened throughout their range (Hicks et al, 2010). The results of this study will provide the conservation authorities with a resource to help them classify this area as a Chimpanzee Conservation Unit (CCU), and, with the support of the local communities, will help inspire further research projects on the Congolese Albertine Rift and in the Ituri highlands, where other undocumented chimpanzee populations occur

| METHODS

| RESULTS

10 Pycnanthus angolensis

Findings

| DISCUSSION