Collectively, Cercocebus and Mandrillus include nine species and two subspecies of African monkeys: seven species of Cercocebus and two of Mandrillus, including two drill subspecies. Together, they represent some of the least studied and hence least known of the Afro-Eurasian Primates. This Plan includes taxon-specific conservation actions, devised under six overarching themes: increase engagement and local livelihood support, reduce knowledge gaps, promote habitat restoration, raise the profile of Cercocebus and Mandrillus taxa, enhance protection, and respond to public health needs for the neighboring human populations. The Plan aimes to raise the profile of the Cercocebus and Mandrillus species, encourage collaboration amongst conservation practitioners, local communities, government agencies, and other invested parties, and ultimately prevent the extinction of some of the most amazing primate species on the planet.

The critically endangered western gorillas (Gorilla gorilla) are divided into two subspecies: the western lowland (G. g. gorilla) and the Cross River (G. g. diehli) gorilla. Given the difficulty in sampling wild great ape populations and the small estimated size of the Cross River gorilla population, only one whole genome of a Cross River gorilla has been sequenced to date, hindering the study of this subspecies at the population level. In this study, we expand the number of whole genomes available for wild western gorillas, generating 41 new genomes (25 belonging to Cross River gorillas) using single shed hairs collected from gorilla nests. By combining these genomes with publicly available wild gorilla genomes, we confirm that Cross River gorillas form three population clusters. We also found little variation in genome-wide heterozygosity among them. Our analyses reveal long runs of homozygosity (>10 Mb), indicating recent inbreeding in Cross River gorillas. This is similar to that seen in mountain gorillas but with a much more recent bottleneck. We also detect past gene flow between two Cross River sites, Afi Mountain Wildlife Sanctuary and the Mbe Mountains. Furthermore, we observe past allele sharing between Cross River gorillas and the northern western lowland gorilla sites, as well as with the eastern gorilla species. This is the first study using single shed hairs from a wild species for whole genome sequencing to date. Taken together, our results highlight the importance of implementing conservation measures to increase connectivity among Cross River gorilla sites.

Tree hyraxes (Dendrohyrax) are one of only three genera currently recognized in Procaviidae, the only extant family in the mammalian order Hyracoidea. Their taxonomy and natural history have received little attention in recent decades. All tree hyrax populations of Guineo-Congolian forests of Africa are currently treated as a single species, Dendrohyrax dorsalis, the western tree hyrax, but many other groups of mammals distributed across this large biome have been shown to consist of several different species, each restricted to a distinct biogeographical region. We analysed variation in loud-call structure, pelage colour, skull morphometrics and mitochondrial genomes in populations across much of the range of D. dorsalis. This integrative approach uncovered considerable cryptic variation. The population found between the Niger and Volta Rivers in West Africa is particularly distinctive, and we describe it herein as a new species. Our study highlights the need to revise the taxonomy of the genus Dendrohyrax in light of modern systematics and current understanding of its distribution. It also adds to a growing body of evidence that the Niger–Volta interfluvium has a distinct meso-mammal fauna. Unfortunately, the fauna of this region is under major threat and warrants much greater conservation attention.

Ranging from forests in Senegal to the Zanzibar Archipelago, red colobus monkeys (Piliocolobus spp.) are the most threatened group of African monkeys. According to the IUCN Red List of Threatened SpeciesTM in 2020, every form of red colobus monkey is threatened with extinction, and 14 of the 18 taxa (>75%) are listed as Critically Endangered or Endangered. Despite their conservation status, only a few populations have been studied in any detail and the general public is largely unaware of these monkeys and their plight. Following over two decades of calls to prioritise red colobus conservation efforts, this publication finally brings together the knowledge of experts on these monkeys and African wildlife conservation to identify the populations in most urgent need of conservation and to develop priority conservation actions for each taxon and across the red colobus’ geographic range.

Overhunting and habitat loss from the expansion of agriculture and extractive industries are the primary threats to primate species, 65% of which are threatened with extinction. In Africa, red colobus (Piliocolobus spp.) are the most endangered group of monkeys due to their vulnerability to these human pressures. The conservation status of the Critically Endangered Preuss’s red colobus (P. preussi), found in southeastern Nigeria and western Cameroon, is not well understood, impeding conservation efforts. We reviewed historical records and recent data on the distribution and abundance of Preuss’s red colobus to assess the species’ population status and provide recommendations for its conservation. Preuss’s red colobus has historically been found in two widely separated populations: one in the contiguous transboundary forests of Nigeria’s Cross River National Park (Oban) and Cameroon’s Korup National Park, and the other in Cameroon’s Ebo–Makombe–Ndokbou forests. Today, Preuss’s red colobus is mostly restricted to Korup and Oban and has largely disappeared from the Ebo–Makombe–Ndokbou forests. Systematic surveys indicate that the population in Korup, where Preuss’s red colobus reaches its highest density, has declined over the last 30 years with possibly 3290–4430 red colobus monkeys remaining. Improving protection of the Korup–Oban population, through improved law enforcement, transboundary conservation, ecological monitoring, and engagement with adjacent local communities, is essential to secure the long-term survival of Preuss’s red colobus. Locating and protecting remnant groups in other forests is also urgently needed. Protecting Preuss’s red colobus will help safeguard some of West Africa’s largest remaining intact forests and other threatened wildlife species.

The Cameroon-Nigeria border region where the Cross River gorilla occurs is a biodiversity hotspot of global significance. The Cross River gorilla can therefore play a role as a 'flagship' species; the actions proposed in this plan ensure the survival of both this Critically Endangered ape and the region's immense biological wealth. This document represents the consensus of experts who met at a workshop in February 2012, in Limbe, South West Region, Cameroon.

the age of 74. Pius was the first Nigerian member of the Primate Specialist Group and during a distinguished career played a leading role in primatology, mammalogy and wildlife conservation in Nigeria. He participated in surveys in the 1980s that led to the re-discovery of wild populations of white-throated monkeys (Cercopithecus erythrogaster) and Sclater's monkeys (Cercopithecus sclateri), two little-known species that had been feared to be possibly extinct; and he helped to establish the Okomu Wildlife Sanctuary (now National Park), a key conservation area for the white-throated monkey and other threatened species, including red-capped mangabeys. Pius was born on 11 November 1940 in Nnewi, in what is now Anambra State, in eastern Nigeria. He grew up in a large, loving family with numerous sisters and brothers, cousins, nieces and nephews. He won a scholarship to study zoology at University College Ibadan (now the University of Ibadan), graduating with a B.Sc. in 1964. His subsequent career was interrupted by the Nigerian civil war. Not long before the outbreak of war in 1967 he relocated to the University of Nigeria, Nsukka, in what was soon to become Biafra. After the conflict began Pius enlisted as an officer in the Biafran army, and was subsequently wounded in the fighting. When the civil war ended in 1970, Pius returned to Ibadan, and, in 1973, completed his doctoral thesis on the ecology and breeding biology of small mammals under the supervision of Dr. David Happold. The data from some of the papers that Pius published based on this research were used for species profiles in the Mammals of Africa (2013), a testimony to the lasting value of his work. In 1979, Pius transferred from Ibadan to the University of Benin, where he was initially a senior lecturer in Zoology and eventually the Acting Head of the Department for Forestry and Wildlife. Increasingly he dedicated himself to the conservation of endangered species and to the protection of the environment in Nigeria, and was one of the first to draw attention to the impact of the commercial bushmeat trade on African forest wildlife. In 1988, he was appointed Executive Director of the Nigerian Conservation Foundation in Lagos and built an international reputation for both himself and the foundation; in 1992, under Pius's leadership , NCF won a UNEP Global 500 Roll of Honour award. After leaving NCF in 1994, Pius worked with the British Council in Lagos …

In the last 40 years, threats to the survival of wild primate populations have greatly increased. Primatologists have long been aware of these threats, and since 1978 have formulated plans to safeguard threatened species. Yet an increasing number of primate species face a high to extremely high risk of extinction. I asked 14 experienced field primatologists for their views on the most serious challenges to more effective primate conservation. They listed habitat loss and hunting as the major direct threats to primate survival, and noted that these activities are driven predominantly by the growth of human populations and the tendency of people to consume resources beyond their immediate survival needs. Two factors identified as most hindering effective action were a lack of political will and insufficient funding, while the main actions recommended to mitigate threats were to undertake more awareness-raising and make protected areas more effective. Such actions have long been recommended, so why have they not worked better? Perhaps the pressures on the natural world are too great to be countered, but I suggest also that too many of the various actors involved in conservation are overly driven by materialism and self-interest. I recommend more attention to the common good and a greater emphasis on the ethical and spiritual reasons for conservation. The International Primatological Society itself could have more vigorous debates on conservation policy at its congresses, and should consider the creation of regional chapters with the aim of promoting primatology in habitat countries.

Habitat loss and fragmentation are among the major threats to wildlife populations in tropical forests. Loss of habitat reduces the carrying capacity of the landscape and fragmentation disrupts biological processes and exposes wildlife populations to the effects of small population size, such as reduction of genetic diversity and increased impact of demographic stochasticity. The Critically Endangered Cross River gorilla Gorilla gorilla diehli is threatened in particular by habitat disturbance because its population is small and it lives in an area where high human population density results in intense exploitation of natural resources. We used remotely-sensed data to assess the extent and distribution of gorilla habitat in the Cross River region and delineated potential dispersal corridors. Our analysis revealed >8,000 km(2) of tropical forest in the study region, 2,500 km(2) of which is in or adjacent to areas occupied by gorillas. We surveyed 12 areas of forest identified as potential gorilla habitat, 10 of which yielded new records of gorillas. The new records expand the known range of the Cross River gorilla by >50%, and support genetic analyses that suggest greater connectivity of the population than previously assumed. These findings demonstrate that considerable connected forest habitat remains and that the area could potentially support a much larger gorilla population if anthropogenic pressures such as hunting could be reduced.

Survival Hope Implementation of the recommendations in this plan will make a significant difference to the survival of the Nigeria-Cameroon chimpanzee. Today, the total population of Nigeria-Cameroon chimpanzees may number as few as 3,500. Implementation of the priority conservation actions proposed in this Conservation Action Plan would protect over 95% of the remaining Nigeria-Cameroon chimpanzees over the next five years.

The status of chimpanzee populations in western Nigeria was poorly known, and they were judged to be highly threatened, and a plan for their conservation needed. Information on the presence, distribution and abundance of chimpanzees in Akure-Ofosu reserve was obtained from interviews and by making wide-ranging reconnaissance surveys in the company of local guides. Ten short series of line-transect censuses was also conducted. Field work was conducted in March-April 2007 and September-October 2007. Three main areas were identified as still supporting chimpanzee populations in Akure-Ofosu Forest Reserve. These are the Premier Gantry/Benin-Olojoda Road Junction, an area called Double Bridge, and east of Jingbe a settlement between Akure-Ofosu and Idanre Forest Reserves. No direct sighting of chimpanzees was achieved however, a total of 33 nests were counted at four sites. Twenty-five (75.8%) of the nests were observed in a single forest block (Double Bridge). The remaining eight nests (24.2%) were observed in two locations within a second forest block (Jingbe). Other primate species encountered include mona monkey, white-throated monkey, putty-nosed monkey and red-capped mangabey. Hunting and intensive exploitation of timber are the main threats to the chimpanzees in the reserve. Akure-Ofosu Forest Reserve does appear to have potential as a chimpanzee conservation site in southwestern Nigeria, especially in combination with such adjacent forests as Idanre. Key words: chimpanzee populations, wide-ranging reconnaissance and forest block

The debate concerning the conservation-related displacement of people in Central Africa remains strongly polarised. In an earlier paper (Curran et al. 2009), we made a clear plea for in-depth, multi-disciplinary research to provide factual assessments of the extent of physical and economic displacements which Kai Schmidt-Soltau and colleagues have referred to in a series of papers (Schmidt-Soltau 2003, 2004, 2005a, b, Brockington 2004, Brockington and Igoe 2006, Brockington et al. 2006, Cernea and Schmidt-Soltau 2003a, b, 2006, Schmidt-Soltau and Brockington 2004, 2007). We also stressed the need to fi nd some ‘common ground’ that would allow all of us concerned with this issue to work together in the interests of both biodiversity conservation and human development. The accusation by Schmidt-Soltau (2009) that conservation organisations willfully continue to commit ‘human rights violations’ in Central Africa is, in our view, not true. We do not dispute that there are examples from around the world where conservation projects have not respected peoples’ rights in the past, and we believe that lessons have been learned and that the conservation approach has shifted accordingly. But citing