The RedList of Threatened species for the DRCongo reports a total of 349 species of which 36 Mammals, 37 Birds, 7 Reptiles, 10 Amphibians, 93 Fishes,43 Molluscs,10 Other Invertebrates, and 113 Plants (UICN, 2016) illustrating the relevance of preforming biodiversity inventories in unexplored regions. This report presents the methods, databases content and general results of a third mission aiming at documenting mammalian and botanical biodiversity in fragmented forests of the Lake Albert escarpment (in short RAFALE) down the Lendu plateau in the Ituri province, Democratic Republic of Congo.
The general objectives of this third mission were to perform line transects and nests counts in order to estimate the density and – combined with camera trap surveys from March till August 2016 – the size of a recently identified isolated eastern chimpanzee population (Pan troglodytes schweinfurthii Giglioli, 1872). We made a first inventory of mammals – mostly primates and rodents -by means of direct and indirect observations along the transects and describe the vegetation, human acitvities and landuse in and around three altitude forest fragments surveyed (800m – 2000m). A total of 5 transects (500 to 1400m) were traced with respectively 2 transects in bloc FG1 and FG2 and 1 transect in FG3 while two random recce in search for new chimpanzee nests were also carried out in FG3 and the south eastern part of FG3 (arbitrarily named FG4). The later was done in order to collect more hairs and faeces - hence genetic material - and estimate the local nest decay rate. Systematic botanical inventories, habitat decription, human activities, nest counts, direct and indirect observations were carried out along 4 of the transects ; rodent trapping was done on 3 main transects, one in each bloc.
A total of 85 perpendicular distances were recorded and ±52 additional nests off the transects (data analysis ongoing) were described to document the preferred tree species on which the local chimpanzee population build their nests. The height of the nest, the state of degradation (fresh or dry), the DBH, and host trees (or support) on which the nests were observed were identified and voucher specimens of selected flora were collected. Besides landuse, and habitat description the level of human activities was also recorded on each transect. Signs and tracks, as well as dung were collected for phylogenetic analysis, diet description and zoonotic infectious agents screening. Camera traps (N=27) were recovered and the images collected to proceed to a general mammalian inventory based on presence/absence of species in the different forest blocks and assess density of a selection
of species per hectare. The images will also allow for the recognition of individual chimpanzees and to compare the number of individuals with the density estimate based on nest counts. In first approximation, a total of at least 26 chimpanzees with 3 unweaned juveniles could be identified in the 25km² area monitored since March 2016. We estimated a chimpanzee density in the RAFALE as follows : 14.25 individuals/km² in FG1, 17.81 individuals/km² in FG2 and 20.82 individuals/km² in FG3 showing an increase in population density as the population density, settlements, and anthropic pressure decreases. One of the camera trap showed a group of 17 chimpanzees patrolling in FG3 block with various specific mutilartions (hand cut or twisted) and facial depigmentation that evokes a skin disease. The faeces and hairs collected from this group could yield an answer as to the condition they suffer. This pioneering work in a remote scientifically neglected area demonstrate the specific diversity and richness of these relict forests and the urgent need for their management and conservation. Inventories and comments on other wildlife species captured by the camera traps and documented in this report demonstrate the richness of these relict forests in the western strip of the Albertine Rift and demonstrate the urgent need for sustainable management, supported by the people and government of Ituri, and conservation measures for these threatened forests.
Relict, refuge and fragmented altitude forest: fauna and flora inventory, and ecological notes on an isolated chimpanzee population (Pan troglodytes schweinfurthii) Djugu Territory, Ituri Province, Democratic Republic of the Congo 30th July – 6th September 2016