High Population Density of Pan troglodytes verus in the Haut Niger National Park, Republic of Guinea: Implications for Local and Regional Conservation

Abstract

The Republic of Guinea harbours the largest population of the endangered western chimpanzees Pan troglodytes verus, and the conservation of this population is regarded as a regional priority. Chimpanzees occur in 3 of the 5 protected areas in Guinea but their conservation status is unknown. We conducted a chimpanzee census in 2001-2002 in the Haut Niger National Park (HNNP), the largest protected area in the country. We counted nests along a total of 103.83 km of transects in the Mafou forest, 1 of the 2 core areas of the park. We recorded a total of 823 nests, of which 38.1% were located in gallery forests, although this habitat type covers only 4.2% of the study site. Using a site-specific mean nest decay rate of 194 days, we estimated the mean density of chimpanzees in the study area at 0.87 weaned individuals/km², the highest density recorded in any West African protected area. A survey conducted in 2008-2009 by other authors in the Mafou forest suggests that the chimpanzee population remained stable over the last 6 yr. Given the significance of the chimpanzee population of the HNNP at the national and international levels, we provide recommendations for its conservation over the long term. Our results highlight the importance of gallery forests as key habitat for chimpanzees in the savannah biome. We therefore recommend that more attention be paid to the conservation of this habitat in land management and conservation planning schemes. In particular, we recommend setting aside gallery forests as ecological corridors between nearby protected areas to maintain exchange between distant chimpanzee populations.

Group Release of Sanctuary Chimpanzees (Pan troglodytes) in the Haut Niger National Park, Guinea, West Africa: Ranging Patterns and Lessons So Far

“…This pattern of habitat usage is similar to that recorded among wild chimpanzees in the HNNP, where feeding remains, nests, as well as direct sightings of wild chimpanzees, were all significantly preferentially recorded in forest habitats (Fleury- Brugiere and Brugiere 2010;Humle et al in review).…”

Population Status of Pan troglodytes verus in Lagoas de Cufada Natural Park, Guinea-Bissau

“…Nest counts are a useful surrogate for estimating ape densities and monitoring their populations over time [47], [48]. Most studies recommend using line transect surveys [15], [18], [49], [50], during which all the nests visible from the transect line are counted either individually [17], [45] or in groups [23], or both [46]. Two nest count techniques are recommended: Standing-Crop Nest Counts (SCNC) and Marked Nest Counts (MNC).…”

“…SCNC consists of only a single visit to all transects, counting all nests irrespective of their age class, whereas MNC consists of counting only nests built between successive visits to the same transect, with all nests removed in the first visit, within an interval short enough to guarantee that no new nests will disappear between repeated visits. SCNC is logistically easier [15], [23], [50], [51], although it requires independent estimates of rates of nest production and nest decay. MNC, on the other hand, is the only alternative when nest decay rate is lacking [17], [18], [46], [51].…”

An analysis of Species Conservation Action Plans in Guinea

“…Conservation of endemic and near-endemic plant species had not been on the national agenda. In contrast, the conservation of large mammals such as the chimpanzee have had high levels of attention (Sugiyama & Soumah 1988, Brugière et al 2005, Fleury-Brugière & Brugière 2010, Humle et al 2011). Following the conclusion of the Darwin and GBIF-BID projects in March 2019, the working group has continued to collaborate to address, review and update 1) Guinea’s CITES list and 2) the second edition of the Guinean National Biodiversity Action Plan.…”