Bonobos (Pan paniscus) inhabit regions south of the Congo River including all areas between its southerly tributaries. To investigate the genetic diversity and evolutionary relationship among bonobo ...populations, we sequenced mitochondrial DNA from 376 fecal samples collected in seven study populations located within the eastern and western limits of the species' range. In 136 effective samples from different individuals (range: 7-37 per population), we distinguished 54 haplotypes in six clades (A1, A2, B1, B2, C, D), which included a newly identified clade (D). MtDNA haplotypes were regionally clustered; 83 percent of haplotypes were locality-specific. The distribution of haplotypes across populations and the genetic diversity within populations thus showed highly geographical patterns. Using population distance measures, seven populations were categorized in three clusters: the east, central, and west cohorts. Although further elucidation of historical changes in the geological setting is required, the geographical patterns of genetic diversity seem to be shaped by paleoenvironmental changes during the Pleistocene. The present day riverine barriers appeared to have a weak effect on gene flow among populations, except for the Lomami River, which separates the TL2 population from the others. The central cohort preserves a high genetic diversity, and two unique clades of haplotypes were found in the Wamba/Iyondji populations in the central cohort and in the TL2 population in the eastern cohort respectively. This knowledge may contribute to the planning of bonobo conservation.
In June 2007, a previously undescribed monkey known locally as "lesula" was found in the forests of the middle Lomami Basin in central Democratic Republic of Congo (DRC). We describe this new species ...as Cercopithecus lomamiensis sp. nov., and provide data on its distribution, morphology, genetics, ecology and behavior. C. lomamiensis is restricted to the lowland rain forests of central DRC between the middle Lomami and the upper Tshuapa Rivers. Morphological and molecular data confirm that C. lomamiensis is distinct from its nearest congener, C. hamlyni, from which it is separated geographically by both the Congo (Lualaba) and the Lomami Rivers. C. lomamiensis, like C. hamlyni, is semi-terrestrial with a diet containing terrestrial herbaceous vegetation. The discovery of C. lomamiensis highlights the biogeographic significance and importance for conservation of central Congo's interfluvial TL2 region, defined from the upper Tshuapa River through the Lomami Basin to the Congo (Lualaba) River. The TL2 region has been found to contain a high diversity of anthropoid primates including three forms, in addition to C. lomamiensis, that are endemic to the area. We recommend the common name, lesula, for this new species, as it is the vernacular name used over most of its known range.
Abstract
Genomic data can be a powerful tool for inferring ecology, behavior, and conservation needs of highly elusive species, particularly, when other sources of information are hard to come by. ...Here, we focus on the Dryas monkey (Cercopithecus dryas), an endangered primate endemic to the Congo Basin with cryptic behavior and possibly <250 remaining adult individuals. Using whole-genome sequencing data, we show that the Dryas monkey represents a sister lineage to the vervets (Chlorocebus sp.) and has diverged from them ∼1.4 Ma with additional bidirectional gene flow ∼750,000–∼500,000 years ago that has likely involved the crossing of the Congo River. Together with evidence of gene flow across the Congo River in bonobos and okapis, our results suggest that the fluvial topology of the Congo River might have been more dynamic than previously recognized. Despite the presence of several homozygous loss-of-function mutations in genes associated with sperm mobility and immunity, we find high genetic diversity and low levels of inbreeding and genetic load in the studied Dryas monkey individual. This suggests that the current population carries sufficient genetic variability for long-term survival and might be larger than currently recognized. We thus provide an example of how genomic data can directly improve our understanding of highly elusive species.
The Endangered dryas monkey Cercopithecus dryas, endemic to the Democratic Republic of the Congo, is one of Africa's most enigmatic primates. The discovery of a dryas monkey killed by a hunter in the ...buffer zone of Lomami National Park in 2014 prompted field research on the species’ distribution, habitat use and stratum preference. We used local knowledge to determine the distribution of this species and to select sites for camera-trap surveys in Lomami National Park and its buffer zone. We employed a multi-strata (0–29 m) camera-trap placement technique to determine habitat use at Camp Bartho in Lomami National Park and Bafundo Forest in the Park's buffer zone. We confirmed the occurrence of the dryas monkey at seven locations over a total area of 3,453 km2, in both the Park and its buffer zone. Dryas monkeys were detected most frequently (2.22 events/100 trap-days) in disturbed areas of Bafundo Forest and less in mature forest in Camp Bartho (0.82 events/100 trap-days). Dryas monkeys appear to prefer structurally complex understories and forest edges. We found that camera traps at 2–10 m above ground over at least 365 trap-days are required to determine if the species is present. We recommend utilizing local knowledge and using this species-specific camera-trap method in other areas of the central Congo basin to determine the wider distribution of the dryas monkey.
Hunting of species not protected by national law and during open hunting season is authorised by Maniema Province regulations in the buffer zone of the Lomami National Park (LNP). Since 2017, ...vouchers tally numbers and species of authorised bushmeat, as well as shotgun ammunition and snare cable transported across LNP on established tracks. The voucher system has high rates of compliance. Vouchers provide proof to park rangers checking caravans that bushmeat was not illegally harvested, and ammunition and snare cable not illegally deployed in LNP. Vouchers facilitate monitoring of bushmeat commerce in about 1/5 of Kindu's bushmeat catchment. Numbers of animals reported in vouchers has declined 2017–2021. However, the proportion of large mammals in bushmeat loads has not declined during this period. This suggests faunal depletion has not occurred in areas sourced by transporters. Insecurity in the area in 2019 led Congolese military to limit shotgun ammunition in transporters loads. This was associated with a decline in numbers of primates in bushmeat loads. Increasing costs and risks of bushmeat transport versus increasing availability and decreasing cost of domestic meat in Kindu have reduced the economic value of bushmeat trade from the LNP buffer zone.
Résumé
La chasse est légale dans la Zone Tampon du Parc National de la Lomami (PNL), Province Maniema, RDC, pendant les saisons où toute chasse n’est pas interdite et pour ce qui concerne les espèces qui ne sont pas complètement protégées par loi nationale. Depuis 2017, a travers un système de jetons émis aux personnes traversant PNL à pied sur quelques pistes bien‐établies, on réussit a comptabilisé le nombre et les espèces des animaux tués et les munitions et nylon/fil métallique des pièges transportés. Les transporteurs conforment facilement à ce système parce qu’un jeton qui est en ordre montre leur légalité s’ils sont arrêtés par un garde du parc. Les jetons permettent de suivre l’ampleur et la nature de la chasse dans 1/5 du secteur entier chassé pour alimenter les marchés de la ville de Kindu. Le nombre d’animaux enregistrés par jeton a diminué de 2017 à 2021, mais la proportion des grands mammifères a resté stable. Ceci indique que la région d’origine n’a pas été surchassée. L’insécurité avec un présence d’inciviques en 2019 a fait que l’armée congolaise a contrôlé la circulation des munitions dans tous les fardeaux des transporteurs; par la suite il y avait une diminution des primates transportés. L’augmentation des coûts de transport et la baisse dans le prix de la viande domestique a aussi réduit les profits à gagner par le commerce en viande de brousse.
Malaria parasites, though widespread among wild chimpanzees and gorillas, have not been detected in bonobos. Here, we show that wild-living bonobos are endemically Plasmodium infected in the ...eastern-most part of their range. Testing 1556 faecal samples from 11 field sites, we identify high prevalence Laverania infections in the Tshuapa-Lomami-Lualaba (TL2) area, but not at other locations across the Congo. TL2 bonobos harbour P. gaboni, formerly only found in chimpanzees, as well as a potential new species, Plasmodium lomamiensis sp. nov. Rare co-infections with non-Laverania parasites were also observed. Phylogenetic relationships among Laverania species are consistent with co-divergence with their gorilla, chimpanzee and bonobo hosts, suggesting a timescale for their evolution. The absence of Plasmodium from most field sites could not be explained by parasite seasonality, nor by bonobo population structure, diet or gut microbiota. Thus, the geographic restriction of bonobo Plasmodium reflects still unidentified factors that likely influence parasite transmission.
The malaria parasite Plasmodium falciparum causes substantial human mortality, primarily in equatorial Africa. Enriched in affected African populations, the B*53 variant of HLA-B, a cell surface ...protein that presents peptide antigens to cytotoxic lymphocytes, confers protection against severe malaria. Gorilla, chimpanzee, and bonobo are humans' closest living relatives. These African apes have HLA-B orthologs and are infected by parasites in the same subgenus (Laverania) as P. falciparum, but the consequences of these infections are unclear. Laverania parasites infect bonobos (Pan paniscus) at only one (TL2) of many sites sampled across their range. TL2 spans the Lomami River and has genetically divergent subpopulations of bonobos on each side. Papa-B, the bonobo ortholog of HLA-B, includes variants having a B*53-like (B07) peptide-binding supertype profile. Here we show that B07 Papa-B occur at high frequency in TL2 bonobos and that malaria appears to have independently selected for different B07 alleles in the two subpopulations.
Examining the relationship between food and primate social organization helps us understand how the environment shaped hominin social evolution. However, there is debate as to whether the social ...differences between our two closest relatives, bonobos (Pan paniscus) and chimpanzees (Pan troglodytes), are due to differences in food availability between their respective habitats or to nonenvironmental factors. The most prominent theory is that bonobo communities have more socially cohesive, stable parties, centered on gregarious females because they evolved in food‐rich habitat where individuals, especially females, are less burdened by competition with groupmates. However, more research on bonobos in habitats with seasonal variation in food is needed. This study measured food availability and bonobo social organization at Luzaka, a new site in a seasonal forest fragment. Fruit abundance and dispersion were recorded for a year at Luzaka with the same methods used at Wamba, a bonobo site in more seasonally stable habitat and terrestrial herbaceous vegetation density was measured. At Luzaka, bonobo parties were also recorded for a year using camera traps. Fruit was more seasonal and dispersed at Luzaka than at Wamba. However, the social organization of Luzaka bonobos resembled social organization of bonobos at less seasonal sites. There were minor effects of fruit clumping on party size without effects on the proportion of females in parties suggesting that at Luzaka, the clumping of fruit slightly affected social cohesiveness but does not disproportionately affect females. Bonobo social cohesiveness and female gregariousness appears consistent and compatible with seasonal habitat.
Research highlights
The female‐centered socially cohesive nature of bonobo social organization is thought to have been shaped by low competition in the food‐rich rainforests where bonobos evolved and has only been well‐studied in such habitat.
This study confirmed that at the southeastern limit of the bonobo range, ripe fruit is more seasonally scarce and dispersed and investigated whether this food seasonality affected bonobo social cohesiveness and female gregariousness using camera traps.
Bonobo social organization is consistent across habitat types: fruit clumping had a small positive effect on party size but fruit availability did not affect female gregariousness.
Understanding the impact of hunting on wildlife is necessary to protect biodiversity in remote, endangered ecosystems, where rural communities depend on bushmeat as sources of food and income. ...Unsustainable hunting has led to a major decline in mammal population densities across Africa, especially for ungulates and primates. The objectives of this study were to (1) quantify the impact of hunting on lesula (
Cercopithecus lomamiensis
), a semiterrestrial and poorly known monkey in the Democratic Republic of the Congo, and (2) assess the species’ relative abundance in the context of its behavioral ecology and local hunting practices. We compared the relative abundance of lesula to prey species preferred by hunters using data collected from camera trap surveys (5,960 days) and primate vocalization surveys (n = 174) and assessed species-specific hunting pressure in the buffer zone using data collected from surveillance patrols (2,255 km), hunter follows (n = 16), and semistructured interviews (n = 21). We found that the abundance of terrestrial mammal and primate species was negatively impacted by hunting in the buffer zone, but the abundance of lesula appeared relatively similar throughout its range. Our results suggest that the relative tolerance of lesula in the buffer zone was associated with its ecological niche and the specific behavior of local hunters. Lesula is a threatened, endemic monkey of the Congo Basin rainforest, and this study provides data to enable its continuous monitoring and long-term population management. Some primate populations, such as lesula, may be able to persist under specific conditions despite being subject to high hunting pressure.
We report here where the most recent common ancestor (MRCA) of bonobos (Pan paniscus) ranged and how they dispersed throughout their current habitat. Mitochondrial DNA (mtDNA) molecular dating to ...analyze the time to MRCA (TMRCA) and the major mtDNA haplogroups of wild bonobos were performed using new estimations of divergence time of bonobos from other Pan species to investigate the dispersal routes of bonobos over the forest area of the Congo River's left bank. The TMRCA of bonobos was estimated to be 0.64 or 0.95 million years ago (Ma). Six major haplogroups had very old origins of 0.38 Ma or older. The reconstruction of the ancestral area revealed the mitochondrial ancestor of the bonobo populations ranged in the eastern area of the current bonobos' habitat. The haplogroups may have been formed from either the riparian forests along the Congo River or the center of the southern Congo Basin. Fragmentation of the forest refugia during the cooler periods may have greatly affected the formation of the genetic structure of bonobo populations.
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