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Agriculture expansion is a major cause of habitat loss and exposure to phytochemical pollution for non-human primates. In addition to endocrine disruption, exposure to pesticides may have other sublethal physiological consequences for animals, such as generation of oxidative damage to macromolecules. In this study, we analyzed the pesticides contained in the river water across the home range of wild chimpanzees (Pan troglodytes) in Sebitoli area located on the Northern part of Kibale National Park (Uganda). We tested whether levels of three urinary markers of oxidative damage vary among individuals in relation to their ranging patterns, as a proxy for pesticide exposure intensity. To better characterize the foraging habitat use, the trophic level, and the energetic status of study individuals, we also quantified urinary levels of carbon and nitrogen stable isotope signatures and of C-peptide. Among the 511 pesticides screened, 18 compounds including herbicides, insecticides, and fungicides were found in the water sampled in the Western part of the home range of chimpanzees. In this area, chimpanzees used to feed on maize crops. By contrast, in the Eastern part where crop feeding was never observed, we found only seven pesticides. According to their ranging patterns and thus crop feeding frequency, the 139 urine samples collected from 43 Sebitoli chimpanzees were categorized as belonging to low, medium, and high exposure level. Chimpanzees from the high exposure zone had higher oxidative DNA damage (8-OHdG) than chimpanzees from both the low and medium exposure groups, who had similar levels of oxidative DNA damage. In addition, individuals with higher C-peptide tended to have significantly higher oxidative DNA damage and lipid peroxides. The three exposure groups had similar levels of urinary 8-isoprostanes and of urinary lipid peroxides. These results were robust for any potential confounding effect of other variables because neither age category nor sex or isotope levels were significantly associated with markers of oxidative damage. Our study points to genotoxic effects as one potential sublethal consequence of ranging in proximity of agricultural fields owing to exposure to pesticides or other unidentified sources of stress. Given our phylogenetic proximity, this information is relevant for the conservation of this species which is endangered and also sentinel for human health. [ABSTRACT FROM AUTHOR]

Every evening, chimpanzees build sleeping "nests" in trees. In some studied communities, individuals appear to be selective about the tree species used, which has led researchers to hypothesize whether chimpanzees prefer trees that repel troublesome insects or/and that provide comfortable and stable structures. We investigate these hypotheses, or a trade-off between both, though study of tree species preference based on their biomechanical and/or biochemical properties in the Sebitoli chimpanzee community in Kibale National Park, Uganda. The ten tree species most frequently used for nesting were compared with ten abundant in their environment but not preferred for nesting. For these 20 tree species, we determined their biomechanical and morphological characteristics such as foliar density, foliar units form (shape and size) and branch rigidity. Their spatial repellent activity, previously tested against Anopheles gambiae was incorporated into the analysis. Chimpanzees chose tree species with medium-sized and elongated foliar units, high foliar density and branch with stiffer wood. In addition, most tree species with such mechanical and morphological properties also have mosquito repellent activity. These tree properties may provide a comfortable sleeping environment enhancing sleep quality. Finally, a comparison across chimpanzee communities would be relevant to understand whether these choices are not only ecological but also cultural. [ABSTRACT FROM AUTHOR]

The expansion of agriculture in equatorial areas is fragmenting and reducing wildlife habitats. For primates, it also increases opportunities to consume crops as high-energy resources, exacerbates conflicts with farmers, and increases exposure to diseases and agrochemicals at the edge of protected areas. In species with sex differences in ranging behavior, individual exposure to such opportunities and threats may vary by sex. Chimpanzees show a great feeding flexibility and are territorial species with varied ranging patterns according to site, sex, or individuals. Within a community whose territory is crossed by a high-traffic road and partially bordered by maize gardens, we tested hypotheses of interindividual differences in access to crops based on age, sex, ranging behavior, and kinship. By analyzing the presence of Sebitoli chimpanzees (Pan troglodytes schweinfurthii , Kibale National Park, Uganda) on video clips from 16 camera traps, we estimated the individual dispersion range across the community's territory and the crop foraging frequency along maize gardens over 16 months. While all age and sex classes were represented at the forest–garden interface, large intrasex differences were observed: some mature males and females were not observed to participate. The crop foraging frequency of adult females in maize gardens was significantly correlated with the location of their ranging areas. Related individuals revealed similar range patterns within the forest territory without sharing crop foraging habits. However, social learning and energy and risks–benefits trade-offs as potential drivers of crop consumption are not excluded. [ABSTRACT FROM AUTHOR]

The IUCN now recognizes the savannah Loxodonta africana and forest Loxodonta cyclotis elephants to be separate species. Despite ecological, behavioural and morphological differences, and different habitat ranges, genetic studies confirm that the two species and hybrids coexist in forest–savannah ecotones. However, the hybrid phenotypes have not yet been described. In this survey we examined whether the phenotypes of the two species and of hybrids can be distinguished. In the first step, we used a machine learning algorithm (K -nearest neighbours) to compare 296 reference images of African elephants from five forest areas and six savannah areas where hybrids have not been recorded, confirming that six morphological criteria can be used to distinguish the species with more than 90% confidence. In the second step, we analysed 1,408 videos of elephants from 14 camera traps in Sebitoli, in Kibale National Park, Uganda, part of the main hybridization area. We used a multiple correspondence analysis and a species assignment key, highlighting the presence of three categories of phenotypes. Compared to the savannah and forest phenotypes (36.8 and 12.1%, respectively), the intermediate phenotypes, which could include hybrids, were more frequent (51.1%). Further studies combining morphology and genetics of the same individuals will be necessary to refine this species assignment key to characterize phenotypes confidently. This non-invasive, fast and inexpensive phenotypical-based method could be a valuable tool for conservation programmes. [ABSTRACT FROM AUTHOR]

Simple Summary: Wild meat is a primary source of protein for many rural populations and its illegal harvest can threaten worldwide wildlife conservation efforts. Near tropical forests, wild meat can be an alternative to domestic meat consumption for different reasons (economy, access, culture, etc.). We aimed to understand drivers of illegal activities affecting wildlife in a hotspot of biodiversity (Sebitoli, Kibale National Park, Uganda) hosting threatened species (including chimpanzees) and bordered by agricultural landscapes with high human densities. Illegal activities were mapped, and individual interviews were conducted. We highlighted that being a young man coming from districts contiguous to Kibale National Park particularly raises the odds of consuming wild meat. This study might help to identify and recommend sustainable social and environmental alternatives to manage biodiversity. The African tropical forests host an inestimable number of resources, including food, medicine, vegetal and animal species. Among them, chimpanzees are threatened with extinction by human activities affecting their habitats, such as forest product harvesting, and/or more directly, snaring and trafficking. We aimed to better understand the spatial distribution of these illegal activities, and the reasons for setting snares and consuming wild meat in an agricultural landscape (subsistence farming and cash crops) densely populated near a protected area (Sebitoli, Northern part of Kibale National Park, Uganda). To carry out this study, we combined GPS records of illegal activities collected with group counts (in total, n = 339 tea workers, 678 villagers, and 1885 children) and individual interviews (n = 74 tea workers, 42 villagers, and 35 children). A quarter of illegal activities collected (n = 1661) targeted animal resources and about 60% were recorded in specific areas (southwest and northeast) of the Sebitoli chimpanzee home range. Wild meat consumption, which is illegal in Uganda, is a relatively common practice among participants (17.1% to 54.1% of respondents depending on actor types and census methods). However, consumers declared that they eat wild meat unfrequently (0.6 to 2.8 times per year). Being a young man coming from districts contiguous to Kibale National Park particularly raises the odds of consuming wild meat. Such an analysis contributes to the understanding of wild meat hunting among traditional rural and agricultural societies from East Africa. [ABSTRACT FROM AUTHOR]

Background: Ticks and tick-borne pathogens significantly impact both human and animal health and therefore are of major concern to the scientific community. Knowledge of tick-borne pathogens is crucial for prescription of mitigation measures. In Africa, much research on ticks has focused on domestic animals. Little is known about ticks and their pathogens in wild habitats and wild animals like the endangered chimpanzee, our closest relative. Methods: In this study, we collected ticks in the forested habitat of a community of 100 chimpanzees living in Kibale National Park, Western Uganda, and assessed how their presence and abundance are influenced by environmental factors. We used non-invasive methods of flagging the vegetation and visual search of ticks both on human team members and in chimpanzee nests. We identified adult and nymph ticks through morphological features. Molecular techniques were used to detect and identify tick-borne piroplasmids and bacterial pathogens. Results: A total of 470 ticks were collected, which led to the identification of seven tick species: Haemaphysalis parmata (68.77%), Amblyomma tholloni (20.70%), Ixodes rasus sensu lato (7.37%), Rhipicephalus dux (1.40%), Haemaphysalis punctaleachi (0.70%), Ixodes muniensis (0.70%) and Amblyomma paulopunctatum (0.35%). The presence of ticks, irrespective of species, was influenced by temperature and type of vegetation but not by relative humidity. Molecular detection revealed the presence of at least six genera of tick-borne pathogens (Babesia, Theileria, Borrelia, Cryptoplasma, Ehrlichia and Rickettsia). The Afrotopical tick Amblyomma tholloni found in one chimpanzee nest was infected by Rickettsia sp. Conclusions: In conclusion, this study presented ticks and tick-borne pathogens in a Ugandan wildlife habitat whose potential effects on animal health remain to be elucidated. [ABSTRACT FROM AUTHOR]

Background: Every evening, chimpanzees (Pan troglodytes) build a sleeping platform so called "nest" by intertwining branches of tree. Most of chimpanzees' communities studied have a preference for tree species in which they nest. As female mosquitoes are feeding on the blood of their host at nighttime, chimpanzees may prevent being disturbed and bitten by mosquitoes by selecting tree species having properties to repel them. Methods: To test the hypothesis that chimpanzees choose tree species for their aromatic properties, data related to 1,081 nesting trees built between 2017 and 2019 in the Sebitoli community of Kibale National Park (Uganda) were analysed. The 10 most used trees were compared to the 10 most common trees in the habitat that were not preferred for nesting. Leaves from the 20 trees species were collected and hydro-distillated to obtain essential oils and one of the by-products for behavioural bioassays against females of the African mosquito, Anopheles gambiae. Results: Sebitoli chimpanzees showed tree preferences: 10 species correspond to more than 80% of the nesting trees. Out of the essential oil obtained from the 10 nesting trees, 7 extracts for at least one concentration tested showed spatial repellency, 7 were irritant by contact and none were toxic. In the other hand, for the abundant trees in their habitat not used by chimpanzees, only 3 were repellent and 5 irritants. Discussion and conclusion: This study contributes to evidence that chimpanzees, to avoid annoying mosquitoes, may select their nesting trees according to their repellent properties (linked to chemical parameters), a potential inspiration for human health. [ABSTRACT FROM AUTHOR]

Some animal species have been presumed to be purely diurnal. Yet, they show flexibility in their activity rhythm, and can occasionally be active at night. Recently, it has been suggested that chimpanzees may rarely engage in nocturnal activities in savannah forests, in contrast to the frequent nocturnal feeding of crops observed at Sebitoli, Kibale National Park, Uganda. Here we thus aimed to explore the factors that might trigger such intense nocturnal activity (e.g. harsher weather conditions during daytime, low wild food availability or higher diurnal foraging risk) in this area. We used camera-traps set over 18 km2 operating for 15 months. We report activities and group composition from records obtained either within the forest or at the forest interface with maize fields, the unique crop consumed. Maize is an attractive and accessible food source, although actively guarded by farmers, particularly during daytime. Out of the 19 156 clips collected, 1808 recorded chimpanzees. Of these, night recordings accounted for 3.3% of forest location clips, compared to 41.8% in the maize fields. Most nocturnal clips were obtained after hot days, and most often during maize season for field clips. At night within the forest, chimpanzees were travelling around twilight hours, while when at the border of the fields they were foraging on crops mostly after twilight and in smaller parties. These results suggest that chimpanzees change their activity rhythm to access cultivated resources when human presence and surveillance is lower. This survey provides evidence of behavioral plasticity in chimpanzees in response to neighboring human farming activities, and emphasizes the urgent need to work with local communities to mitigate human-wildlife conflict related to crop-feeding. [ABSTRACT FROM AUTHOR]

Pesticides are used worldwide with potential harmful effects on both fauna and flora. The Kibale National Park in Uganda, a site renowned for its biodiversity is surrounded by tea, banana and eucalyptus plantations as well as maize fields and small farms. We previously showed presence of pesticides with potential endocrine disruptive effects in the vicinity. To further investigate the water pollution linked to agricultural pressure in this protected area, we implemented a complementary monitoring strategy based on: analytical chemistry, effects based methods and the deployment of Polar Organic Chemical Integrative Samplers (POCIS). Chemical analysis of the POCIS extracts revealed the presence of 13 pesticides: carbofuran, DEET, 2.4-D amine, carbaryl, ametryn, isoproturon, metolachlor, terbutryn, dimethoate, imidacloprid, picaridin, thiamethoxam, carbendazim, with the first three being present in the largest quantities. Water samples collected at the POCIS sampling sites exhibited thyroid and estrogen axis disrupting activities in vivo , in addition to developmental and behaviour effects on Xenopus laevis tadpoles model. Based on our observations, for the health of local human and wildlife populations, further monitoring as well as actions to reduce agrochemical use should be considered in the Kibale National Park and in regions exposed to similar conditions. Image 1 • The Kibale national park (KNP) in Uganda is a hotspot of biodiversity. • Wildlife in the northern part of KNP is threatened by the presence of phytochemicals. • Chemical analysis of local river water revealed the presence of 13 pesticides. • Local river water exhibited thyroid and estrogen disrupting activities in vivo. • Further monitoring and pesticide usage reduction should be considered in KNP. Water collected in Kibale national park in Uganda contains 13 pesticides and exhibits thyroid and estrogen axis disruption in aquatic larvae. [ABSTRACT FROM AUTHOR]

Design: Observations of wild chimpanzees (Pan troglodytes schweinfurthii) were conducted in Kibale National Park, Uganda, at the sites of Sebitoli and Ngogo. Results: We report the first two cases of cleft lip in wild chimpanzees. Additionally, some other chimpanzees in the Sebitoli community show facial dysplasia and congenital anomalies, such as patches of depigmented hairs and limb defects. Conclusions: Cleft lip has been documented in several species of nonhuman primates, but much remains unknown about the occurrence of cleft lip and cleft palate in great apes, probably because such malformations are rare, wild apes are difficult to monitor and observe, and severe cases associated with cleft palates render suckling impossible and lead to early death of infants. The genetic basis of such defects in great apes warrants investigation, as does the possibility that environmental toxins contribute to their etiology in Kibale in ways that could affect humans as well. [ABSTRACT FROM AUTHOR]

Background: Malaria parasites (Plasmodium sp.), including new species, have recently been discovered as low grade mixed infections in three wild chimpanzees (Pan troglodytes schweinfurthii) sampled randomly in Kibale National Park, Uganda. This suggested a high prevalence of malaria infection in this community. The clinical course of malaria in chimpanzees and the species of the vectors that transmit their parasites are not known. The fact that these apes display a specific behaviour in which they consume plant parts of low nutritional value but that contain compounds with anti-malarial properties suggests that the apes' health might be affected by the parasite. The avoidance of the night-biting anopheline mosquitoes is another potential behavioural adaptation that would lead to a decrease in the number of infectious bites and consequently malaria. Methods: Mosquitoes were collected over two years using suction-light traps and yeast-generated CO2 traps at the nesting and the feeding sites of two chimpanzee communities in Kibale National Park. The species of the female Anopheles caught were then determined and the presence of Plasmodium was sought in these insects by PCR amplification. Results: The mosquito catches yielded a total of 309 female Anopheles specimens, the only known vectors of malaria parasites of mammalians. These specimens belonged to 10 species, of which Anopheles implexus, Anopheles vinckei and Anopheles demeilloni dominated. Sensitive DNA amplification techniques failed to detect any Plasmodium-positive Anopheles specimens. Humidity and trap height influenced the Anopheles capture success, and there was a negative correlation between nest numbers and mosquito abundance. The anopheline mosquitoes were also less diverse and numerous in sites where chimpanzees were nesting as compared to those where they were feeding. Conclusions: These observations suggest that the sites where chimpanzees build their nests every night might be selected, at least in part, in order to minimize contact with anopheline mosquitoes, which might lead to a reduced risk in acquiring malaria infections. [ABSTRACT FROM AUTHOR]

This study focused on Oeosophagostomum sp., and more especially on O. bifurcum, as a parasite that can be lethal to humans and is widespread among humans and monkeys in endemic regions, but has not yet been documented in apes. Its epidemiology and the role played by non-human primates in its transmission are still poorly understood. O. stephanostomum was the only species diagnosed so far in chimpanzees. Until recently, O. bifurcum was assumed to have a high zoonotic potential, but recent findings tend to demonstrate that O. bifurcum of non-human primates and humans might be genetically distinct. As the closest relative to human beings, and a species living in spatial proximity to humans in the field site studied, Pan troglodytes is thus an interesting host to investigate. Recently, a role for chimpanzees in the emergence of HIV and malaria in humans has been documented. In the framework of our long-term health monitoring of wild chimpanzees from Kibale National Park in Western Uganda, we analysed 311 samples of faeces. Coproscopy revealed that high-ranking males are more infected than other individuals. These chimpanzees are also the more frequent crop-raiders. Results from PCR assays conducted on larvae and dried faeces also revealed that O. stephanostomum as well as O. bifurcum are infecting chimpanzees, both species co-existing in the same individuals. Because contacts between humans and great apes are increasing with ecotourism and forest fragmentation in areas of high population density, this paper emphasizes that the presence of potential zoonotic parasites should be viewed as a major concern for public health. Investigations of the parasite status of people living around the park or working inside as well as sympatric non-human primates should be planned, and further research might reveal this as a promising aspect of efforts to reinforce measures against crop-raiding. Author Summary: The disease caused by the nodular worm Oesophagostomum bifurcum can be lethal in humans and is thus of major human health significance in certain African regions. There are still gaps in the understanding of the epidemiology of the disease, including the role of non-human primates as reservoirs of the infection. We recently conducted a survey in a community of wild chimpanzees (Pan troglodytes schweinfurthii) in Kibale National Park, Western Uganda. O. stephanostomum is so far the only species previously found in chimpanzees. A total of 311 stool samples was examined and revealed that high-ranking males are more infected than other individuals. These chimpanzees are also the more frequent crop-raiders. Moreover, we reported for the first time molecular evidence for O. bifurcum in addition to O. stephanostomum in chimpanzees. Our results raise public health concerns for a neglected infection in regions where spatial proximity between great apes and humans are increasing because of forest fragmentation. [ABSTRACT FROM AUTHOR]

Abstract: Wild chimpanzees eat several plant species claimed by traditional healers to cure diseases. However, the behaviour leading apes to ingest these peculiar species is not clearly understood. Some of the items consumed by chimpanzees have low nutritional value, and there is a growing body of evidence suggesting that health might be improved or regulated by such ingestion. Observations concerning the diet and the health condition of wild chimpanzees (Pan troglodytes schweinfurthii) in the Kibale National Park (Uganda) are discussed in relation to the ethnomedicinal utilization of plant species reviewed in literature. Among the 163 plant parts known to be eaten by these chimpanzees, at least 35 (21.4%) are used in traditional medicine as treatments for intestinal parasites, skin infections, reproduction and respiratory diseases. Relationships with pharmacological properties are presented, taking into account the difficulties of interpreting ethnomedicinal data. In conclusion, a greater knowledge of ape''s behaviour and health may provide a new complementary method to select plants for biomedical research. [Copyright &y& Elsevier]

We assessed the health status of chimpanzees (Pan troglodytes schweinfurthii) of the Kanyawara group in the Kibale National Park in Western Uganda via noninvasive methods. We conducted visual veterinary inspection, parasitological and urine analysis in association with behavioral observations, causing minimal disturbance or stress to individually recognized chimpanzees. We applied multiple parasitological techniques to 252 stool samples to compare their efficacy in detecting parasitic infection and to increase the power of detecting a wide range of parasites at a more sensitive level. We examined 76 urine samples via a quick detection method to evaluate multiple parameters of urine that indicate organ dysfunction. Results of the different analyses are mutually supportive and provided useful information for monitoring bodily condition and diseases. The multifaceted health evaluation system is a beneficial tool for monitoring long-term and short-term changes in health status due to environmental stress, seasonal dietary change, and disease in wild chimpanzee populations. Use of this method to detect changes in health, when employed together with behavioral observations, may also provide important insights into the potential effects of self-medicative behaviors. [ABSTRACT FROM AUTHOR]

Abstract: Ethnopharmacological relevance: The study was done to establish medicinal plants used in the treatment of various diseases by the people in the Northern sector of Kibale National Park in western Uganda. It was also aimed at establishing the plant parts used and the mode of preparation of remedies. These plants create a basis for phytochemical evaluation which can lead to the discovery of biologically active compounds that can be used as starting materials in the development of new drugs targeting selected diseases such as malaria. Materials and methods: The required information was obtained using open interviews, semi-structured questionnaires, focus group discussions and transect walks. Results: Different medicinal plants (131 species) distributed over 55 families were observed to be used by the local communities around the Northern sector of Kibale National Park. The plants as reported in this paper are used to treat 43 physical illnesses/diseases. The most used parts of the plants are the leaves. Water is the main medium used for the preparation of the remedies which are mostly administered orally. Conclusion: The people in the study area have a rich heritage of traditional plants that are used in the health care system to treat diseases. These medicinal plants have contributed significantly to several disease therapies. The most common diseases treated are malaria and cough, which are mostly treated by Vernonia amygdalina Del. and Albizia coriaria Welw. respectively. The main sources of medicinal plants include bush land, home gardens, grasslands, and the forest. [Copyright &y& Elsevier]

Abstract: Aim of the study: In Uganda, malaria is the most common disease and Ugandan people largely rely on traditional medicine. In this context, we carried out an ethnobotanical study on the Kiohima village, located close to the Kibale National Park in South-Western Uganda and investigated in vitro the antiplasmodial and cytotoxic activities of selected medicinal plants. Materials and methods: Seventy-five plants-using adults (men and women) were interviewed to find out their plant use. From these information, 48 plants used in traditional medicine were identified and according to their reported uses and to bibliographic data, several parts of 28 plants (leaves, barks, roots), were selected and collected for biological evaluations. These samples were dried, extracted with ethyl acetate and the crude extracts were assayed for in vitro antiplasmodial and cytotoxic activities at 10μg/mL. Results: One third of the screened plants showed a significant antiplasmodial activity with inhibition greater than 50% at 10μg/mL. Conclusion: These results may indicate a possible explanation of the use of some medicinal plant against malaria in the village of Kiohima and have also allowed to highlight a plant with potent antimalarial activity: Citropsis articulata root barks. [Copyright &y& Elsevier]

Abstract: In the framework of the phytochemical investigation of plant species eaten by wild chimpanzees in their natural environment in Uganda, leaf samples of Markhamia lutea were selected and collected. The crude ethyl acetate extract of M. lutea leaves exhibited significant in vitro anti-parasitic activity and low cytotoxicity against MRC5 and KB cells. Fractionation of this extract led to six cycloartane triterpenoids, musambins A–C and their 3-O-xyloside derivatives musambiosides A–C. The structures were elucidated on the basis of spectral studies including mass spectroscopy and extensive 2D NMR. Most of the compounds exhibited mild anti-leishmanial and anti-trypanosomal activities. [Copyright &y& Elsevier]

Wildlife is increasingly exposed to environmental pollution, but data illustrating to what extent this exposure can impact health and survival of endangered species is missing. In humans, hair matrix analysis is a reliable tool for assessing cumulative exposure to organic pollutants such as pesticides but has rarely been used in other primates for this purpose. LC/MS-MS and GC/MS-MS multi-residue methods were used to screen the presence of 152 organic pollutants and their metabolites belonging to 21 different chemical families in hair samples from our closest relative, the chimpanzee. Samples were collected from 20 wild chimpanzees in Sebitoli, Kibale National Park, Uganda and 9 captive chimpanzees in the Réserve Africaine de Sigean, France. In total, 90 chemicals were detected, 60 in wild chimpanzees and 79 in captive chimpanzees. The median concentrations of detected chemicals in captive individuals were significantly higher than those in wild chimpanzees. Hair from the captive individuals at RAS was sampled a second time after 6 months in an environment of reduced exposure to these pollutants (diet of organic food, decreased use of plastic food and water containers). The number of chemicals detected in captive chimpanzees reduced from 79 to 63, and their concentrations were also significantly reduced. In the present study we report for the first time the use of hair analysis to detect organic pollutants in primate hair. We conclude that both wild and captive chimpanzees are exposed to a large range of different chemicals through their diet. Our study provides surprising and alarming evidence that besides the direct threats of poaching, deforestation and diseases, wild chimpanzees might be endangered by indirect consequences of anthropic activities. As chimpanzees are our closest relatives, our results should be considered as an alert for human health as well., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

While road network expansion is crucial for economic development, it can cause a notable disturbance of fauna, especially in protected area in terms of habitat fragmentation, risk of collision, and also indirect threat such as pollution. In this study, we monitored the 4.6-km long tarmac road crossing the Kibale National Park in Uganda, home to a rich variety of wild species including the endangered chimpanzees. We evaluated the effects of collisions and pollution, as well as the impact of the renovation process in terms of disturbance and the mitigation measures deployed. This survey reports the death of 24 wild animals killed by cars, including two chimpanzees. The atmospheric concentrations of O 3 , NO 2 , SO 2 , and BTEX did not exceed recommended limits. More than 5000 plastic bottles were collected along the road within 4 months, and for the first time, the presence of BPA and BPS was detected in the hairs of wild chimpanzees. The road bisecting the Kibale National Park poses a high danger in terms of traffic and an underestimated risk related to plastic pollution. Measures (signpost, speed bumps) should be urgently deployed to decrease the risk posed by the renovated road for emblematic species such as chimpanzees, which are crucial for tourism and economy in Uganda.

Background: Primate populations are in decline, mainly affected by agriculture leading to habitat loss, fragmentation but also chemical pollution. Kibale National Park (Uganda), Sebitoli forest, surrounded by tea and crop fields, is the home range of chimpanzees presenting congenital facial dysplasia. This study aimed to identify to what extent the same phenotypical features are observed in baboons (Papio anubis) of this area., Methods: A total of 25 390 clips recorded by 14 camera traps between January 2017 and April 2018 were analyzed., Results: We identified 30 immature and adult baboons of both sexes with nose and lip deformities. They were more frequently observed in the northwestern part of the area., Conclusions: A possible effect of pesticides used in crops at the border of their habitat is suspected to alter the embryonic development. This study emphasizes the importance of non-invasive methods to detect health problems in wild primates that can act as sentinels for human health., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Nodular Oesophagostomum genus nematodes are a major public health concern in some African regions because they can be lethal to humans. Their relatively high prevalence in people has been described in Uganda recently. While non-human primates also harbor Oesophagostomum spp., the epidemiology of this oesophagostomosis and the role of these animals as reservoirs of the infection in Eastern Africa are not yet well documented., Methodology/principal Findings: The present study aimed to investigate Oesophagostomum infection in terms of parasite species diversity, prevalence and load in three non-human primates (Pan troglodytes, Papio anubis, Colobus guereza) and humans living in close proximity in a forested area of Sebitoli, Kibale National Park (KNP), Uganda. The molecular phylogenetic analyses provided the first evidence that humans living in the Sebitoli area harbored O. stephanostomum, a common species in free-ranging chimpanzees. Chimpanzees were also infected by O. bifurcum, a common species described in human populations throughout Africa. The recently described Oesophagostomum sp. found in colobine monkeys and humans and which was absent from baboons in the neighboring site of Kanyawara in KNP (10 km from Sebitoli), was only found in baboons. Microscopic analyses revealed that the infection prevalence and parasite load in chimpanzees were significantly lower in Kanyawara than in Sebitoli, an area more impacted by human activities at its borders., Conclusions/significance: Three different Oesophagostomum species circulate in humans and non-human primates in the Sebitoli area and our results confirm the presence of a new genotype of Oesophagostomum recently described in Uganda. The high spatiotemporal overlap between humans and chimpanzees in the studied area coupled with the high infection prevalence among chimpanzees represent factors that could increase the risk of transmission for O. stephanostomum between the two primate species. Finally, the importance of local-scale research for zoonosis risk management is important because environmental disturbance and species contact can differ, leading to different parasitological profiles between sites that are close together within the same forest patches.

Despite the spread of road infrastructures throughout Africa to support regional development, industry, and tourism, few studies have examined how wild animals adapt their behavior and ecology in road-forest ecotones. Indeed, while numerous studies have demonstrated chimpanzee adaptability in anthropogenic landscapes, none have examined the effects of asphalted highways on wild chimpanzee behaviors. In a 29-month survey, we assessed the dangers posed by an asphalted road crossing the Sebitoli area of Kibale National Park (Uganda). We analyzed 122 individual chimpanzee crossings. Although the asphalted road represents a substantial threat to crossing animals (89 motorized vehicles per hour use this road and individuals of six different primate species were killed in 1 year), chimpanzees took into account this risk. More than 90% of the individuals looked right and left before and while crossing. Chimpanzees crossed in small subgroups (average 2.7 subgroups of 2.1 individuals per crossing event). Whole parties crossed more rapidly when chimpanzees were more numerous in the crossing groups. The individuals most vulnerable to the dangers of road crossing (females with dependents, immature, and severely injured individuals) crossed less frequently compared with non-vulnerable individuals (lone and healthy adolescents and adults). Moreover, healthy adult males, who were the most frequent crossing individuals, led progressions more frequently when crossing the road than when climbing or descending feeding trees. Almost 20% of the individuals that crossed paid attention to conspecifics by checking on them or waiting for them while crossing. These observations are relevant for our understanding of adaptive behavior among chimpanzees in human-impacted habitats. Further investigations are needed to better evaluate the effects of busy roads on adolescent female dispersal and on their use of territories. Mitigation measures (e.g., bridges, underpasses, reduced speed limits, speed-bumps, signposts, or police controls) should be established in this area., (© 2015 Wiley Periodicals, Inc.)

In a rapidly changing landscape highly impacted by anthropogenic activities, the great apes are facing new challenges to coexist with humans. For chimpanzee communities inhabiting encroached territories, not bordered by rival conspecifics but by human agricultural fields, such boundaries are risky areas. To investigate the hypothesis that they use specific strategies for incursions out of the forest into maize fields to prevent the risk of detection by humans guarding their field, we carried out video recordings of chimpanzees at the edge of the forest bordered by a maize plantation in Kibale National Park, Uganda. Contrary to our expectations, large parties are engaged in crop-raids, including vulnerable individuals such as females with clinging infants. More surprisingly chimpanzees were crop-raiding during the night. They also stayed longer in the maize field and presented few signs of vigilance and anxiety during these nocturnal crop-raids. While nocturnal activities of chimpanzees have been reported during full moon periods, this is the first record of frequent and repeated nocturnal activities after twilight, in darkness. Habitat destruction may have promoted behavioural adjustments such as nocturnal exploitation of open croplands.

Landscape patterns and chimpanzee (Pan troglodytes schweinfurthii) densities in Kibale National Park show important variation among communities that are geographically close to one another (from 1.5 to 5.1 chimpanzees/km2). Anthropogenic activities inside the park (past logging activities, current encroachment) and outside its limits (food and cash crops) may impact the amount and distribution of food resources for chimpanzees (frugivorous species) and their spatial distribution within the park. Spatial and temporal patterns of fruit availability were recorded over 18 months at Sebitoli (a site of intermediate chimpanzee density and higher anthropic pressure) with the aim of understanding the factors explaining chimpanzee density there, in comparison to results from two other sites, also in Kibale: Kanyawara (low chimpanzee density) and Ngogo (high density, and furthest from Sebitoli). Because of the post-logging regenerating status of the forest in Sebitoli and Kanyawara, smaller basal area (BA) of fruiting trees most widely consumed by the chimpanzees in Kanyawara and Sebitoli was expected compared to Ngogo (not logged commercially). Due to the distance between sites, spatial and temporal fruit abundance in Sebitoli was expected to be more similar to Kanyawara than to Ngogo. While species functional classes consumed by Sebitoli chimpanzees (foods eaten during periods of high or low fruit abundance) differ from the two other sites, Sebitoli is very similar to Kanyawara in terms of land-cover and consumed species. Among feeding trees, Ficus species are particularly important resources for chimpanzees at Sebitoli, where their basal area is higher than at Kanywara or Ngogo. Ficus species provided a relatively consistent supply of food for chimpanzees throughout the year, and we suggest that this could help to explain the unusually high density of chimpanzees in such a disturbed site.

Certain toxic plants are beneficial for health if small amounts are ingested infrequently and in a specific context of illness. Among our closest living relatives, chimpanzees are found to consume plants with pharmacological properties. Providing insight on the origins of human self-medication, this study investigates the role social systems and physiology (namely gut specialization) play on learning mechanisms involved in the consumption of unusual and potentially bioactive foods by two great ape species. We collected data from a community of 41-44 wild chimpanzees in Uganda (11 months, 2008), and a group of 11-13 wild western gorillas in Central African Republic (10 months, 2008-2009). During feeding, we recorded food consumed, its availability, and social interactions (including observers watching conspecifics and the observers' subsequent activity). Unusual food consumption in chimpanzees was twice higher than in gorillas. Additionally chimpanzees relied more on social information with vertical knowledge transmission on unusual foods by continually acquiring information during their life through mostly observing the fittest (pre-senescent) adults. In contrast, in gorillas observational learning primarily occurred between related immatures, showing instead the importance of horizontal knowledge transmission. As chimpanzees' guts are physiologically less specialized than gorillas (more capable of detoxifying harmful compounds), unusual-food consumption may be more risky for chimpanzees and linked to reasons other than nutrition (like self-medication). Our results show that differences in sociality and physiology between the two species may influence mechanisms that discriminate between plants for nutrition and plants with potential therapeutic dietary components. We conclude that self-medication may have appeared in our ancestors in association with high social tolerance and lack of herbivorous gut specialization., (Copyright © 2011 Elsevier Inc. All rights reserved.)

We measured the biological activities of a selected sample (84 crude extracts) of 24 species eaten by wild chimpanzees (Pan troglodytes schweinfurthii) in the Kibale National Park, western Uganda, to assess their potential chemotherapeutic values. Antibacterial, antimalarial, and/or antileishmania activities were observed in some crude extracts, and five of these extracts showed a significant cytotoxicity against human tumor cells. Active compounds isolated from three plant parts occasionally ingested by chimpanzees (Diospyros abyssinica (Ebenaceae) bark, Uvariopsis congensis (Annonaceae) leaves, and Trichilia rubescens (Meliaceae) leaves) showed highly significant medicinal properties. Two novel antiparasitic limonoids were isolated from Trichilia rubescens and their molecular structures were determined. In addition to elucidating the natural equilibrium maintained between hosts and pathogens, our investigation of the diet of wild chimpanzees may serve as a guideline to discovering plants with bioactive properties that should be preserved from destruction because of their health maintenance value for great ape populations., (2006 Wiley-Liss, Inc.)

Three new oleanane-type triterpene saponins (1-3), named grandibracteosides A-C, were isolated from the methanolic extract of leaves of Albizia grandibracteata, a species consumed by primates in the Kibale National Park, Uganda. The structures of the saponins were established using 1D and 2D NMR experiments and mass spectrometry and confirmed by acid and alkaline hydrolysis. The crude extract and the pure compounds showed significant inhibitory activity against KB and MCF7 tumoral cell lines in vitro. The compounds are glycosides of acacic acid acylated by an o-aminobenzoyl unit. This is the first report of such ester saponins in dicotyledonous plants. Studies of the primate diet may provide a useful method for finding naturally occurring compounds of medicinal significance.

Following a veterinary and behavioral survey of chimpanzees from a natural population in Uganda, leaf samples of Trichilia rubescens were collected because of the unusual method of ingestion observed. The methanolic crude extract of T. rubescens leaves exhibited significant antimalarial activity in vitro. Bioassay-directed fractionation provided two new limonoids, trichirubines A and B. A greater understanding of the role of secondary compounds in the primate diet may be helpful in recovering naturally occurring compounds of medicinal significance for human medicine.