Publications by authors named "Samuel Angedakin"

Since 2005, the leading cause of death for western chimpanzees () at Tacugama Chimpanzee Sanctuary (TCS) in Sierra Leone has been epizootic neurologic and gastroenteric syndrome (ENGS), associated with the bacterium (family ). The prevalence of at TCS in clinically normal chimpanzees and the environment remains unknown, as does its distribution in other captive and wild chimpanzee populations and their environments across Africa. The aim of this study was to determine the distribution and prevalence of bacteria in sanctuary and wild chimpanzee populations across Africa and to identify demographic and ecological risk factors for in chimpanzees and the environment.

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The diversity and composition of mammal communities are strongly influenced by human activities, though these relationships may vary across broad scales. Understanding this variation is key to conservation, as it provides a baseline for planning and evaluating management interventions. We assessed variation in the structure and composition of Afrotropical medium and large mammal communities within and outside protected areas, and under varying human impact.

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Ongoing ecosystem change and biodiversity decline across the Afrotropics call for tools to monitor the state of biodiversity or ecosystem elements across extensive spatial and temporal scales. We assessed relationships in the co-occurrence patterns between great apes and other medium to large-bodied mammals to evaluate whether ape abundance serves as a proxy for mammal diversity across broad spatial scales. We used camera trap footage recorded at 22 research sites, each known to harbor a population of chimpanzees, and some additionally a population of gorillas, across 12 sub-Saharan African countries.

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Strontium isotope (Sr/Sr) analysis with reference to strontium isotope landscapes (Sr isoscapes) allows reconstructing mobility and migration in archaeology, ecology, and forensics. However, despite the vast potential of research involving Sr/Sr analysis particularly in Africa, Sr isoscapes remain unavailable for the largest parts of the continent. Here, we measure the Sr/Sr ratios in 778 environmental samples from 24 African countries and combine this data with published data to model a bioavailable Sr isoscape for sub-Saharan Africa using random forest regression.

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Article Synopsis
  • Scientists study how animals change to survive in different places, which is really important for understanding biology.
  • They looked at chimpanzees, our closest relatives, who live in many types of environments like rainforests and savannahs.
  • By examining genetic information from wild chimpanzees, they discovered that some chimps have adapted to fight off malaria in similar ways to humans, showing how important genetic diversity is for endangered animals.
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Wild chimpanzees (Pan troglodytes) are caught in snares set for other animals and sometimes injure or lose body parts. Snaring can compromise the health, growth, survival, and behavior of chimpanzees and, thus, represents a threat for the conservation of this endangered species. During a long-term study of chimpanzees at Ngogo in Kibale National Park, Uganda, we started a project to remove snares in and around their territory.

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Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species' population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate 'intactness scores': the remaining proportion of an 'intact' reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region's major land uses (urban, cropland, rangeland, plantation, protected, etc.

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Many anthropogenic-driven changes, such as hunting, have clear and immediate negative impacts on wild primate populations, but others, like climate change, may take generations to become evident. Thus, informed conservation plans will require decades of population monitoring. Here, we expand the duration of monitoring of the diurnal primates at Ngogo in Kibale National Park, Uganda, from 32.

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Article Synopsis
  • This study provides the first comprehensive catalog of chimpanzee genetic diversity using non-invasive samples collected from 48 sites in Africa, focusing on chromosome 21.
  • The research reveals clear genetic differences among the four recognized chimpanzee subspecies and indicates unexpected local genetic exchanges, while also mapping patterns of population isolation, migration, and connectivity.
  • Unlike humans, chimpanzees lack a history of long-distance migrations, which may affect their cultural transmission, and the study introduces a precise geolocation method for identifying the origins of confiscated chimpanzees.
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Viruses closely related to human pathogens can reveal the origins of human infectious diseases. Human herpes simplexvirus type 1 (HSV-1) and type 2 (HSV-2) are hypothesized to have arisen via host-virus codivergence and cross-species transmission. We report the discovery of novel herpes simplexviruses during a large-scale screening of fecal samples from wild gorillas, bonobos, and chimpanzees.

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Article Synopsis
  • Chimpanzees show diverse behaviors and inhabit various environments, but they are considered a discontinuous species with four subspecies separated by historical geography.
  • Genetic studies reveal that most of their genetic structure is influenced by distance rather than strict subspecies boundaries, indicating some geographic barriers were not effective in preventing gene flow.
  • Ongoing human impacts and habitat fragmentation threaten their genetic diversity, suggesting urgent conservation efforts are needed to maintain healthy populations.
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Noninvasive samples as a source of DNA are gaining interest in genomic studies of endangered species. However, their complex nature and low endogenous DNA content hamper the recovery of good quality data. Target capture has become a productive method to enrich the endogenous fraction of noninvasive samples, such as faeces, but its sensitivity has not yet been extensively studied.

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Large brains and behavioural innovation are positively correlated, species-specific traits, associated with the behavioural flexibility animals need for adapting to seasonal and unpredictable habitats. Similar ecological challenges would have been important drivers throughout human evolution. However, studies examining the influence of environmental variability on within-species behavioural diversity are lacking despite the critical assumption that population diversification precedes genetic divergence and speciation.

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Herpesviruses are thought to have evolved in very close association with their hosts. This is notably the case for cytomegaloviruses (CMVs; genus ) infecting primates, which exhibit a strong signal of co-divergence with their hosts. Some herpesviruses are however known to have crossed species barriers.

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Temperament and personality research in humans and nonhuman animals measures behavioral variation in individual, population, or species-specific traits with implications for survival and fitness, such as social status, foraging, and mating success [1-5]. Curiosity and risk-taking tendencies have been studied extensively across taxa by measuring boldness and exploration responses to experimental novelty exposure [3, 4, 6-15]. Here, we conduct a natural field experiment using wildlife monitoring technology to test variation in the reaction of wild great apes (43 groups of naive chimpanzees, bonobos, and western gorillas across 14 field sites in Africa) to a novel object, the camera trap.

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Article Synopsis
  • Chimpanzees are known for having many different ways of acting and culture, similar to humans.!
  • The "disturbance hypothesis" says that when humans disturb chimpanzee habitats, it harms their ability to learn and share behaviors.!
  • A study showed that chimpanzees living in places with a lot of human activity behave much less normally, meaning we need to protect both their homes and their cultures for conservation efforts.!
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We describe and document with digital images two adult male baboons (Papio anubis) from the Kibale National Park, Uganda who were infected with some kind of disease having clinical signs suggestive of Treponema pallidum. One of these males was missing his premaxilla, part of the maxilla, upper incisors, canines, and possibly the first premolars. The condition of his scrotum was not seen.

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Large-scale genomic studies of wild animal populations are often limited by access to high-quality DNA. Although noninvasive samples, such as faeces, can be readily collected, DNA from the sample producers is usually present in low quantities, fragmented, and contaminated by microorganism and dietary DNAs. Hybridization capture can help to overcome these impediments by increasing the proportion of subject DNA prior to high-throughput sequencing.

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Chimpanzees are traditionally described as ripe fruit specialists with large incisors but relatively small postcanine teeth, adhering to a somewhat narrow dietary niche. Field observations and isotopic analyses suggest that environmental conditions greatly affect habitat resource utilisation by chimpanzee populations. Here we combine measures of dietary mechanics with stable isotope signatures from eastern chimpanzees living in tropical forest (Ngogo, Uganda) and savannah woodland (Issa Valley, Tanzania).

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Objectives: We investigated occurrences and patterns of terrestrial nocturnal activity in wild chimpanzees (Pan troglodytes) and modelled the influence of various ecological predictors on nocturnal activity.

Methods: Data were extracted from terrestrial camera-trap footage and ecological surveys from 22 chimpanzee study sites participating in the Pan African Programme: The Cultured Chimpanzee. We described videos demonstrating nocturnal activity, and we tested the effects of the percentage of forest, abundance of predators (lions, leopards and hyenas), abundance of large mammals (buffalos and elephants), average daily temperature, rainfall, human activity, and percent illumination on the probability of nocturnal activity.

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Target-capture approach has improved over the past years, proving to be very efficient tool for selectively sequencing genetic regions of interest. These methods have also allowed the use of noninvasive samples such as faeces (characterized by their low quantity and quality of endogenous DNA) to be used in conservation genomic, evolution and population genetic studies. Here we aim to test different protocols and strategies for exome capture using the Roche SeqCap EZ Developer kit (57.

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