Understanding the dynamics of inter-group cooperation in human adaptation has been the subject of recent empirical and theoretical studies in evolutionary anthropology, beginning to fill gaps in our knowledge of how interactions across political, economic and social domains can – and often do – lead to stable, large-scale cooperation. Here we investigate dyadic intergroup cooperation in shotgun hunting in the Republic of the Congo. In the Congo Basin, inter-group cooperation between foragers and farmers is at the centre of an exchange system maintained by traditional norms and institutions such as fictive kinship. Here, we focused on what factors predict cooperative shotgun hunting exchanges between BaYaka and Yambe. We conducted structured interviews with 48 BaYaka hunters and 18 Yambe men who organise hunts in a village along the Motaba River. We used Bayesian multilevel regression models to investigate the influence of Yambe and BaYaka attributes on probability of dyadic cooperation. We found that BaYaka men's reputations as skilled hunters and their family size each predicted cooperation in shotgun hunting, whereas there was no effect of Yambe attributes (status, wealth, family size). We discuss the results in terms of evolutionary models of men as hunters and inter-group cooperation, as well as biodiversity conservation implications.

Transmission electron microscopy (TEM) and analytical electron microscopy (AEM) methods were used to study the crystal chemistry of phyllosilicates occurring in green grains of Miocene sediments from the Congo continental shelf. Using diagrams based on wt. % K and the (Fe + Mg)/Al ratio, minerals were distinguished from mixed-layer phases. The most abundant detrital mineral is Fe-kaolinite. The morphology and composition identify this mineral as a component of ferralitic soils. This Fe-rich kaolinite has undergone a complex process of partial dissolution and recrystallization and further enrichment in Fe and, to a lesser extent, in Mg in the marine environment. The detrital mica observed with TEM retains the original morphology and chemistry of muscovite. Alteration processes resulted in the crystallization of 1:1 trioctahedral Fe2+ and Mg-rich minerals and interstratified phases with 1:1 and 2:1 layers in varying proportions observed with the aid of high-resolution transmission electron microscopy (HRTEM) imaging. Included among the newly formed 7-Å phases are those apparently containing excess Si. The smectites are apparently neoform, and chemical analyses showed that these marine K-smectites belong to the beidellite-nontronite series and have tetrahedral substitutions similar to muscovite. Their compositions are closer to beidellite than to nontronite, although the latter was observed in association with goethite. The TEM observations and crystallochemical data show that mineral alteration ceased after forming mixed-layer minerals, and alteration did not reach the glauconitization stage. Apparently, the Miocene assemblages experienced rapidly changing environmental conditions and high sedimentation rates that continue today.

We document a process initiated by Indigenous Peoples in Cameroon that seeks to open a dialogue with key conservation actors to work towards community-led, rights-based alternatives to so-called fortress conservation. In June 2021, Gbabandi, a platform of forest Indigenous Peoples, invited key conservation actors to a 1-day listening event. This represented an important precedent, reversing the usual approach to dialogue in which Indigenous Peoples are invited to participate at various levels in externally directed processes. In this case the space for engagement was opened by Indigenous Peoples on their own terms based on Indigenous ways of organizing, and conservation organizations were invited to participate. Indigenous Peoples gave testimonies of physical violence and abuse in various protected areas across Cameroon. Conservation actors acknowledged there had been violations of human rights and there was substantial discussion about threats to wildlife and the need for more inclusive approaches to conservation, redevelopment of management plans and renegotiation of access for Indigenous communities based on community consent. The long-term impact remains to be seen but the immediate effect of an Indigenous-led process was that key decision makers in conservation in Cameroon heard directly from the people affected by their decisions and, since the event, have been more active than previously in contacting and consulting Indigenous Peoples about how protected areas are managed. Gbabandi is hopeful that this type of initiative will change the dialogue between communities and protected area managers and will lead to real changes in conservation practice.

The Congo basin forests have vast conservation potential but because of their inaccessibility and periodic insecurity there is little formal protection or ecological research occurring there. Community-based conservation efforts in the unprotected forest corridor separating Kahuzi-Biega and Maiko National Parks in eastern Democratic Republic of the Congo aim to protect a unique forest ecosystem and facilitate the development of ecological research. To support this process, we obtained baseline data on the occurrence of terrestrial mammals in the Nkuba Conservation Area by conducting camera-trap (2014–2018) and transect (2013–2018) surveys. From camera-trap images we also extracted diel activity patterns and estimated overlap in these patterns between selected pairs of species. We identified 29 mammal species weighing > 1 kg using camera traps and 22 species in transect surveys, with a total of 33 mammal species, of which seven are categorized as threatened on the IUCN Red List. Among this mammalian community, we recorded nocturnal and diurnal species with short core activity periods, and several cathemeral species with long activity periods, with various degrees of temporal separation of diel activity between species. The presence of threatened species, including the Critically Endangered Grauer's gorilla Gorilla beringei graueri, suggests that the Nkuba Conservation Area harbours a forest community that requires continuous monitoring, further research and investment in protection from the ongoing deforestation and resource exploitation occurring in the surrounding region.

Large frugivores provide critical seed dispersal services for many plant species and their extirpation from forested ecosystems can cause compositional shifts in regenerating plant cohorts. Yet, we still poorly understand whether large seed-dispersers have complementary or redundant roles for forest regeneration. Here, to assess the functional complementarity of large-bodied frugivores in forest regeneration, we quantified the effects of varying abundance of hornbills, primates and the forest elephant on the density, species richness and the mean weighted seed length of animal-dispersed tree species among seedlings in five sites in a forest–savanna mosaic in D. R. Congo, while accounting for percentage forest cover and the local presence of fruiting trees. We found that the abundance of primates was positively associated with species richness of seedlings, while percentage forest cover was negatively associated (R2 = 0.19). The abundance of hornbills, the presence of elephants and percentage forest cover were positively associated with mean seed length of the regenerating cohort (R2 = 0.13). Spatially explicit analysis indicated that some additional processes have an important influence on these response indices. Primates would seem to have a preponderant role for maintaining relatively high species richness, while hornbills and elephant would seem to be predominantly responsible for the recruitment of large-seeded trees. Our results could indicate that these taxa of frugivores play complementary functional roles for forest regeneration. This suggests that the extirpation of one or more of these dispersers would likely not be functionally compensated for by the remaining taxa, hence possibly cascading into compositional shifts.

Apes, like many frugivorous animals, are crucial allies for the reproduction of several fruiting tree species. Almost all apes, however, including bonobos Pan paniscus, are threatened with extinction. How will this affect tree conservation? How can plants that are adapted to seed dispersal by apes reproduce without their dispersal vectors? At LuiKotale, in an evergreen tropical forest of the Democratic Republic of Congo, the recruitment of 22 plant species in the absence of seed dispersal was investigated under the parental canopy, where a proportion of seeds fall without horizontal dissemination. Most bonobo-dispersed plant species (95% of 19 species) were unable to self-recruit under the canopy. As 40% of the tree species (65% of trees) at LuiKotale are dispersed by bonobos there is a risk of ecosystem decay and simplification (reduced biodiversity) if Pan paniscus disappears from its natural range. The extinction of other apes from their forests could have similar consequences. The conservation of tree species, therefore, must encompass conservation of pollinators, seed dispersal vectors and other species that provide ecological services to the trees and other fruiting plants.

Survival of Afrotropical primary forests depends not only on habitat protection but also on the protection of animal species such as frugivorous primates, recognized as the most important seed dispersers for many plants. Here we investigate seed-dispersal services by the bonobo (Pan paniscus) in an evergreen lowland tropical rain forest of the Congo Basin. In the long-term research site of LuiKotale, we investigated food habits and seed processing based on 22 mo of behavioural observation, seed trial experiment and long-term daily GPS tracking of a habituated ape community. Bonobos were mainly frugivores (66% of all feeding sessions), spending about 3.5 h d−1 swallowing seeds that were transported for an average of 24 h in the gut. On average, an individual bonobo dispersed 172 kg y−1 of seeds (or 220000 seeds y−1) of more than 91 plant species by endozoochory over an average distance of 1.2 km from the parent tree. Passed seeds germinated more rapidly, more successfully and had greater post-dispersal survival than unpassed seeds. Bonobo-dispersed plants accounted for 40% of tree species and 65% of individual trees in the study site (12 1-ha plots census). Since bonobos show little functional overlap with other frugivores, the loss of their seed-dispersal services is likely to affect forest structure and dynamics. Our results justify description of the threatened bonobo as a gardener of the Congo forest.

The external factors that influence the environmental, social and economic performance of logging companies were studied using a questionnaire submitted to 30 logging concessions in five countries of the Congo Basin. This paper analyses socioeconomic constraints and environmental impacts experienced by these concessions, as well as their response to major external drivers of change. Concessionaires considered investment and operating finance their main constraint, followed by insufficient technical and human capacities, and inconsistent application of official regulations. Environmental problems directly produced by concessions' operations represented around one-third of the total score for environmental problems reported. Damage caused by construction of logging roads and erosion were identified as the main issues. Induced problems (two-thirds of the total score) were dominated by hunting, with encroachment and illegal logging perceived as much less significant. Policies, infrastructure, markets and technology are key external drivers of change in concessions' practices, while regional and international forestry institutions reportedly have the least influence, reflecting an emerging scepticism about the proliferation of international institutions and initiatives promoting sustainable forestry.

In the debt-ridden, high-population-growth, resource-mining states of the Congo Basin, conservation of biodiversity is seldom the primary concern of national policy makers or of local resource users. Moreover, the recurring costs of managing protected areas and the opportunity costs of forgoing logging and farming to maintain protected areas are a substantial net drain on national and local economies. Consequently, it is becoming increasingly important that protected areas generate, from user fees or donor contributions, sufficient funds to offset the costs of maintaining them. Government and donor investment currently meet less than 30 per cent of the estimated recurring costs required to manage the protected-area network within central African countries effectively, and cover none of the growing opportunity costs. Nature tourism, the fastest growing sector of the $US3 trillion (3 million million) a year global tourism industry, may offer a source of revenue to help fill this gap in funds. Congo Basin national parks and reserves harbour many charismatic animals (okapi, lowland gorilla, mandrills, bongo, forest elephant) that are likely to attract tourists, and as a result many protected- area managers are sinking capital into the development of tourist infrastructure. This paper reviews the evidence for ecotourism's capacity to generate revenue for protected-area management and appraises the financial viability of nature tourism in the Congo Basin.