Browsing by Author "Krief, Sabrina"

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    Agricultural expansion as risk to endangered wildlife: Pesticide exposure in wild chimpanzees and baboons displaying facial dysplasia
    (Science of the Total Environment, 2017) Krief, Sabrina; Berny, Philippe; Gumisiriza, Francis; Gross, Régine; Demeneix, Barbara; Baptiste Fini, Jean; Chapman, Colin A.; Chapman, Lauren J.; Seguya, Andrew; Wasswa, John
    Prenatal exposure to environmental endocrine disruptors can affect development and induce irreversible abnormalities in both humans and wildlife. The northern part of Kibale National Park, a mid-altitude rainforest in western Uganda, is largely surrounded by industrial tea plantations and wildlife using this area (Sebitoli) must cope with proximity to human populations and their activities. The chimpanzees and baboons in this area raid crops (primarily maize) in neighboring gardens. Sixteen young individuals of the 66 chimpanzeesmonitored (25%) exhibit abnormalities including reduced nostrils, cleft lip, limb deformities, reproductive problems and hypopigmentation. Each pathology could have a congenital component, potentially exacerbated by environmental factors. In addition, at least six of 35 photographed baboons from a Sebitoli troop (17%) have similar severe nasal deformities. Our inquiries in villages and tea factories near Sebitoli revealed use of eight pesticides (glyphosate, cypermethrin, profenofos, mancozeb, metalaxyl, dimethoate, chlorpyrifos and 2,4-D amine). Chemical analysis of samples collected from 2014 to 2016 showed that mean levels of pesticides in fresh maize stems and seeds, soils, and river sediments in the vicinity of the chimpanzee territory exceed recommended limits. Notably, excess levels were found for total DDT and its metabolite pp′-DDE and for chlorpyrifos in fresh maize seeds and in fish from Sebitoli. Imidacloprid was detected in coated maize seeds planted at the edge the forest and in fish samples from the Sebitoli area, while no pesticides were detected in fish from central park areas. Since some of these pesticides are thyroid hormone disruptors, we postulate that excessive pesticide use in the Sebitoli area may contribute to facial dysplasia in chimpanzees and baboons through this endocrine pathway. Chimpanzees are considered as endangered by IUCN and besides their intrinsic value and status as closely related to humans, they have major economic value in Uganda via ecotourism. Identifying and limiting potential threats to their survival such be a conservation priority.
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    All-You-Can-Eat: Influence of Proximity to Maize Gardens on the Wild Diet and the Forest Activities of the Sebitoli Chimpanzee Community in Kibale National Park
    (MDPI AG, 2022-03) Couturier, Chloé; Bortolamiol, Sarah; Ortmann, Sylvia; Okimat, John-Paul; Asalu, Edward; Krief, Sabrina
    Abstract Frugivorous primates have developed several strategies to deal with wild fruit scarcity, such as modifying their activity budget or enlarging their diet. Agricultural expansion threatens primate habitats and populations (e.g., disease transmission, agrochemical exposure), but it also increases crop feeding opportunities. We aimed at understanding whether maize presence close to the natural habitat of chimpanzees, a threatened species, would lead to significant behavioral modifications. We monitored 20 chimpanzees over 37 months in Kibale National Park, Uganda, with maize gardens at the forest edge. Based on focal nest-to-nest data, we analyzed their diet, activity budget, and energy balance depending on wild fruit and maize availability. We found that the Sebitoli area is a highly nutritive habitat for chimpanzees, with large and caloric wild fruits available all year long. The chimpanzees opportunistically consume maize and exploit it by resting less during maize season. However, no significant variation was found in daily paths and energy expenditures according to maize availability. No behavioral or energy modification was observed regarding wild resources either. Despite the availability of nutritious domestic resources, chimpanzees still exploit wild fruits and do not limit their movements. Thus, their contribution to seed dispersal and forest regeneration in this area is not affected.
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    Cycloartane triterpenes from the leaves of Neoboutonia macrocalyx L.
    (Elsevier, 2014) Namukobe, Jane; Kiremire, Bernard T.; Byamukama, Robert; Kasenene, John M.; Dumontet, Vincent; Guéritte, Françoise; Krief, Sabrina; Florent, Isabelle; Kabasa, John D
    Neoboutonia macrocalyx is used by people in south western Uganda around Kibale National Park in the treatment of malaria. Phytochemical investigation on the leaves of this plant led to the isolation of nine cycloartane triterpenes (1–9) and one phenanthrene; 7-methoxy-2,8 dimethyl-9, 10-dihydrophenantherene-3,6 diol (10) along with three known compounds which included 22-de-Oacetyl- 26-deoxyneoboutomellerone (11), mellerin B (12) and 6-hydroxystigmast-4-en-3-one (13). The chemical structures of the compounds were established mainly through a combination of spectroscopic techniques. The isolated compounds were evaluated for antiplasmodial activity against the chloroquine-resistant FcB1/Colombia strain of Plasmodium falciparum and for cytotoxicity against the KB (nasopharyngeal epidermoid carcinoma) and MRC-5 (human diploid embryonic lung) cells. Seven out of 13 compounds exhibited good antiplasmodial activity with IC50 of 65 lg/ml with two compounds exhibiting low cytotoxicity and five compounds having significant cytotoxicity.
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    Phenotypical characterization of African savannah and forest elephants, with special emphasis on hybrids: the case of Kibale National Park, Uganda
    (Cambridge University Press (CUP), 2022-06) Bonnald, Julie; Cornette, Raphaël; Pichard, Maëllie; Asalu, Edward; Krief, Sabrina
    Abstract Abstract 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.
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    Traditional plants used for Medicinal purposes by local communities around the Northern sector of Kibale National Park, Uganda
    (Elsevier, 2011) Namukobe, Jane; Kasenene, John.M.; Kiremire, Bernard T.; Byamukama, Robert; Kamatenesi-Mugisha, Maud; Krief, Sabrina; Dumontet, Vincent; Kabasa, John D.
    Ethnopharmacological relevance: The study was done to establish medicinal plants used in the treatmentof various diseases by the people in the Northern sector of Kibale National Park in western Uganda. Itwas also aimed at establishing the plant parts used and the mode of preparation of remedies. Theseplants create a basis for phytochemical evaluation which can lead to the discovery of biologically activecompounds that can be used as starting materials in the development of new drugs targetingselected 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.
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    Who are the elephants living in the hybridization zone? How genetics may guide conservation to better protect endangered elephants
    (Elsevier B.V, 2021-12) Bonnald, Julie; Utge, Jose; Kuhner, Mary K.; Wasser, Samuel K.; Asalu, Edward; Okimat, John Paul; Krief, Sabrina
    Abstract After a long-standing debate, African elephants are now considered by the IUCN as two distinct species: savannah elephants (Loxodonta africana), listed as endangered on the IUCN Red List of Threatened Species, and forest elephants (Loxodonta cyclotis), critically endangered. Both are severely threatened by forest loss, fragmentation and degradation due to agriculture expansion, as well as by illegal ivory trade. Although the two species have different habitat preferences, their range overlaps in some ecotones; despite an ancient separation between these two species, hybrids have been reported in five locations. The main hybrid hotspot is located on the Democratic Republic of Congo-Uganda border and still remains understudied. Using 15 microsatellites, we investigated this hybridization zone by determining the species and hybrid status of 177 fecal samples collected in the area of Sebitoli, at the extreme North of Kibale National Park. Surprisingly for a forest area, no pure forest elephants were detected. Out of the 91 individuals sampled, a very large proportion (81.3%) were hybrid individuals mainly from a second generation or more. Only 18.7% of pure savannah elephants were detected, all originating from the DRC-Uganda border. Further analyses are necessary to assess the age of this hybridization zone. Our results emphasize that hybrids and savannah elephants can successfully range in forested area. They also show that forest elephants are rare even in their native habitat. In the current context of high threat faced by African elephant species, it is crucial to strengthen conservation efforts for these species before it is too late.