Mammal distribution and trends in the threatened Ebo 'intact forest landscape', Cameroon

Intact forest landscapes (IFLs) are globally important for maintaining functional ecosystems. Ebo forest (~1400 km2) in Cameroon is one of the largest remaining IFLs in the Cross-Sanaga-Bioko coastal forest ecoregion and harbours several IUCN Red-Listed threatened mammal species. We evaluated the status, trends, and distribution of mammals ≥ 0.5 kg in the Ebo forest over 12 years using guided recce and camera trap monitoring surveys, as well as local knowledge to inform future land use and conservation planning. Recce monitoring of seven taxa (blue duiker Philantomba monticola, chimpanzee Pan troglodytes, forest elephant Loxodonta cyclotis, putty-nosed monkey Cercopithecus nictitans, medium sized duikers Cephalophus spp., and red river hog Potamochoerus porcus) showed that some are stable or increasing. Indeed, our recent camera trap data confirmed breeding Gorilla gorilla (western gorilla) and elephant. Distribution models for chimpanzees and elephants showed that their populations are concentrated in the centre of the forest, away from human pressure. Some other species, however, including red colobus Piliocolobus preussi, leopard Panthera pardus, African golden cat Caracal aurata, and forest buffalo Syncerus caffer nanus are either close to extirpation or have been extirpated within living memory. We conclude that the Ebo intact forest landscape retains an important mammal community, despite no formal legal protection. Ebo’s future is uncertain, with two commercial logging concessions announced by Cameroon in 2020 and later suspended in response to national and international pressure. It is crucial to maintain Ebo’s integrity to maintain the biodiversity and function of this important part of the Cross-Sanaga-Bioko coastal forest ecoregion

Montane grassland resources drive gorilla (Gorilla gorilla) nesting behaviors in the Ebo forest, Littoral Region, Cameroon

peer reviewedGreat apes show strong attachment to their nesting sites, which provide them with substantial survival elements. Their nesting behaviors are influenced by geographical and ecological variables including habitat type, slope, elevation gradients, and sometimes anthropogenic pressures. This study aimed to assess environmental variables that influenced Ebo gorillas’ (Gorilla gorilla) nesting behavior in relation to nesting site selection, nest types, and nesting materials. We collected data from January 2013 to November 2017 along reconnaissance tracks (recce, hereafter) using the marked nest counting method. We recorded an encounter rate of 0.16 nesting sites per km, with an average number of four nests per gorilla group. The mean nest diameter was 90.33 ± 23.92 cm (n = 640, range 25–199 cm). Ebo gorillas preferred nesting sites at high altitude located in grassland areas with open canopy, ligneous undergrowth composition, and very closed visibility. They used more than 281 plant species as materials for nesting, with Marantaceae and Zingiberaceae species being the most common material used. Terrestrial herbaceous nests were the most common nest type (55%). During the dry season, gorillas visited more often the mature forest habitat and mostly constructed arboreal nests. Finally, reuse of nesting sites was minimal (16%), and re-visitation intervals ranged from 3 days to 33 months. Our study is the first systematic investigation of gorilla nesting behavior within the Ebo forest, constituting therefore an important starting point for the long-term conservation planning for this little-known population.Ebo Forest Research Project, Cameroo