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result(s) for
"Djagoun, Chabi A. M. S."
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Can DNA help trace the local trade of pangolins? Conservation genetics of white-bellied pangolins from the Dahomey Gap (West Africa)
by
Djossa, Bruno
,
Olayemi, Ayodeji
,
Djagoun, Chabi A. M. S.
in
Africa, Western
,
Analysis
,
Animal Systematics/Taxonomy/Biogeography
2022
Background
African pangolins are currently experiencing unprecedented levels of harvesting, feeding both local demands and the illegal international trade. So far, the lack of knowledge on the population genetics of African pangolins has hampered any attempts at assessing their demographic status and tracing their trade at the local scale. We conducted a pioneer study on the genetic tracing of the African pangolin trade in the Dahomey Gap (DG). We sequenced and genotyped 189 white-bellied pangolins from 18 forests and 12 wildlife markets using one mitochondrial fragment and 20 microsatellite loci.
Results
Tree-based assignment procedure showed that the pangolin trade is endemic to the DG region, as it was strictly fed by the the Dahomey Gap lineage (DGL). DGL populations were characterized by low levels of genetic diversity, an overall absence of equilibrium, important inbreeding levels, and lack of geographic structure. We identified a 92–98% decline in DGL effective population size 200–500 ya—concomitant with major political transformations along the ‘Slave Coast’—leading to contemporaneous estimates being inferior to minimum viable population size (< 500). Genetic tracing suggested that wildlife markets from the DG sourced pangolins through the entire DGL range. Our loci provided the necessary power to distinguish among all the genotyped pangolins, tracing the dispatch of a same individual on the markets and within local communities. We developed an approach combining rarefaction analysis of private allele frequencies with cross-validation of observed data that traced five traded pangolins to their forest origin, c. 200–300 km away from the markets.
Conclusions
Although the genetic toolkit that we designed from traditional markers can prove helpful to trace the illegal trade in pangolins, our tracing ability was limited by the lack of population structure within the DGL. Given the deleterious combination of genetic, demographic, and trade-related factors affecting DGL populations, the conservation status of white-bellied pangolins in the DG should be urgently re-evaluated.
Journal Article
Geographic distribution and supply chain of vultures in Benin, West Africa
by
Dognimon, Samson
,
Djagoun, Chabi A. M. S.
,
Zanvo, Stanislas
in
Data collection
,
Decision making
,
distribution
2025
Illegal trade poses a significant threat to African vultures, particularly in Benin, which stands as the second major hotspot for vultures' trade in West Africa. To address gaps in research on distribution, supplying habitat sources and trade dynamics, we conducted semi‐structured interviews with 150 sellers in traditional medicine markets (TMM) and surveyed 590 local residents in villages surrounding five protected areas. We used a chord diagram to visually represent the frequency of reports of countries involved in the trade, and mapped local ecological knowledge (LEK)‐based geographic distribution of vultures across Benin. Our findings revealed that seven West African countries, as well as Cameroon from Central Africa supplied vulture specimens to TMM. We recorded 491 vultures specimens from various species such as Hooded, white‐headed, white‐backed, Rüppell's, Egyptian, and lappet‐faced vulture. Among the six vulture species recorded in TMM, five were still found in Benin, primarily in the north of the country. Our study provides insights into the supply chain and LEK‐based geographic distribution of vultures in Benin. It highlights the pressing need for further research using conventional methods to study the diversity and distribution of vultures in Benin, as well as concerted and coordinated conservation interventions to support vulture populations in the region.
Journal Article
Distribution patterns of fire regime in the Pendjari Biosphere Reserve, West Africa
by
Djagoun, Chabi A. M. S.
,
Zoffoun, Omobayo G.
,
Sogbohossou, Etotépé A.
in
arid lands
,
Biodiversity
,
Biosphere
2023
Pendjari Biosphere Reserve (PBR), a primary component of the W-Arly-Pendjari transboundary biosphere reserve, represents the largest intact wild ecosystem and pristine biodiversity spot in West Africa. This savannah ecosystem has long been affected by fire, which is the main ecological driver for the annual rhythm of life in the reserve. Understanding the fire distribution patterns will help to improve its management plan in the region. This study explores the fire regime in the PRB during 2001–2021 in terms of burned area, seasonality, fire frequency, and mean fire return interval (MFRI) by analysing moderate resolution imaging spectroradiometer (MODIS) burned area product. Results indicated that the fire season in the PBR extends from October to May with a peak in early dry season (November–December). The last two fire seasons (2019–2020 and 2020–2021) recorded the highest areas burned in the PBR out of the twenty fire seasons studied. During the twenty years period, 8.2% of the reserve burned every 10–11 months and 11.5% burned annually. The largest part of the reserve burned every one to two years (63.1%), while 8.3% burned every two to four years, 5.8% burned every four to ten years, and 1.9% burned every ten to twenty years. Only 1.3% of the entire area did not fire during the whole study period. Fire returned to a particular site every 1.39 a and the annual percentage of area burned in the PBR was 71.9%. The MFRI (MFRI<2.00 a) was low in grasslands, shrub savannah, tree savannah, woodland savannah, and rock vegetation. Fire regime must be maintained to preserve the integrity of the PBR. In this context, we suggest applying early fire in tree and woodland savannahs to lower grass height, and late dry season fires every two to three years in shrub savannah to limit the expansion of shrubs and bushes. We propose a laissez-faire system in areas in woodland savannah where the fire frequency is sufficient to allow tree growth. Our findings highlight the utility of remote sensing in defining the geographical and temporal patterns of fire in the PBR and could help to manage this important fire prone area.
Journal Article
DNA Barcoding Silver Butter Catfish (Schilbe intermedius) Reveals Patterns of Mitochondrial Genetic Diversity Across African River Systems
2020
The silver butter catfish (
Schilbe intermedius
) is widely distributed across African river systems. To date, information on its mitochondrial genetic diversity, population structure, and historical demography are not well-established. Herein, we combined newly generated mitochondrial cytochrome c oxidase (
COI
) subunit I gene sequences with previously published
COI
sequences in the global databases to reconstruct its phylogeography, population genetic structure, and historical demography. Results from the mtDNA phylogeography and species delimitation tests (Cluster algorithm – Species Identifier, Automatic Barcode Gap Discovery and Poison Tree Process model) revealed that
S. intermedius
comprises at least seven geographically defined matrilines. Although the overall haplotype diversity of
S. intermedius
was high (h = 0.90), results showed that East (Kenya) and West (Nigeria) African populations had low levels of haplotype diversity (h = ~0.40). In addition, population genetic polymorphism and historical demographics showed that
S. intermedius
populations in both East and West Africa underwent severe contractions as a result of biogeographic influences. The patterns of genetic diversity and population structure were consistent with adaptive responses to historical biogeographic factors and contemporary environmental variations across African river systems. This is suggestive of the influence of historical biogeographic factors and climatic conditions on population divergence of
S. intermedius
across African river systems. Given our discovery of previously underappreciated diversity within
S. intermedius
, we recommend that this species be considered for increased conservation and management.
Journal Article
Developing policy-relevant biodiversity indicators: lessons learnt from case studies in Africa
by
Djagoun, Chabi A M S
,
Akpona, Hugues Adeloui
,
de Bisthoven, Luc Janssens
in
Biodiversity
,
biodiversity indicators
,
capacity building
2019
There is an increasing need for monitoring schemes that help understand the evolution of the global biodiversity crisis and propose solutions for the future. Indicators, including temporal baselines, are crucial to measure the change in biodiversity over time, to evaluate progress towards its conservation and sustainable use and to set conservation priorities. They help design and monitor national and regional policies on biodiversity; they also feed into national reporting on international agreements such as the Convention on Biological Diversity and the Sustainable Development Goals. We analyse the methodological approach of five small African projects resulting from a call to promote indicator development, improve monitoring capacity and strengthen the science-policy interface in the field of biodiversity. We compared their approach to existing guidance provided by the international community, specifically the Biodiversity Indicators Partnership. To this end, we assess whether internationally recommended steps are effectively applied to national/local biodiversity monitoring in selected developing countries. We also present lessons learnt from workshop interactions between partners involved in these projects. Through our pilot projects we identified data availability and data accessibility, together with the involvement of stakeholders, as critical steps in indicator development. Moreover, there is a need for a better awareness and a wider application of the indicator concept itself. Hence, training of key actors both in the policy and science spheres is needed to operationalize indicators and ensure their continuity and sustainability. We hope that these case studies and lessons learnt can stimulate and support countries in the Global South to formulate policy-relevant biodiversity indicators.
Journal Article
Modeling population extirpation rates of white‐bellied and giant pangolins in Benin using validated local ecological knowledge
by
Djossa, Bruno
,
Djagoun, Chabi A. M. S.
,
Zanvo, Stanislas
in
area of occupancy
,
Deforestation
,
distribution area
2023
Pangolins are globally threatened by unsustainable hunting for local use and illegal international trade, plus habitat loss. In Benin (West Africa), white‐bellied and giant pangolins have experienced a contraction in their distribution areas and population decline during the last two decades. To better understand the factors underlying declines in these species, we investigated extirpation rates of populations over the last 20 years. Because pangolins are elusive species difficult to monitor by standard methods, the status of populations has been assessed through a local ecological knowledge (LEK) approach. We collected information on persistence or extirpation status of pangolins from 156 localities. A binomial model was built to predict population persistence probability as a function of past and ongoing landscape changes, initial abundance (1998), human pressures, and density of the protected area network. The LEK‐based model was highly accurate (97% correct classification rate) in predicting the presence of white‐bellied pangolin in 52 localities where its presence has been confirmed independently. According to model outputs, persistence probability of pangolins is positively related to distance to main road, initial population abundance, and negatively related to deforestation, shrinkage of favorable habitat, and distance to protected areas. When those factors are controlled for, the white‐bellied pangolin has a higher probability of persistence than the giant pangolin. Even assuming no further habitat change, the distribution area of the white‐bellied pangolin is predicted to keep decreasing against an unavoidable extinction of the giant pangolin in Benin in the next two decades. Besides validating the usefulness of LEK as a population assessment method, this study emphasizes that, despite a demonstrated positive effect of protected areas, the current situation is not sustainable for pangolins and calls for urgent conservation actions to stop or reduce overhunting. Using LEK combined with direct evidence, a binomial model was built to predict population persistence probability as a function of past and ongoing landscape changes, initial abundance (1998), human pressures, and density of the protected areas' network. LEK‐based model was highly efficient (97% of correct classification) in predicting the presence of the white‐bellied pangolin in 52 localities where its presence has been confirmed independently. According to model outputs, persistence probability of pangolins is positively related to distance to main road, initial population abundance, and negatively related to deforestation, shrinkage of favourable habitat, and distance to protected areas.
Journal Article
Hunting affects dry season habitat selection by several bovid species in northern Benin
2014
Multiple land uses including tourism, hunting, and agriculture around protected areas can be a serious complication for wildlife management. We calculated habitat selection indices (Manly's alpha) for 10 bovid species in the Pendjari Biosphere Reserve in Benin, west Africa, to assess if habitat use differed in each bovid species between hunting and non-hunting zones. Presence/absence data was used in resource-selection functions based on a generalized linear mixed effect model to examine factors that explained bovid species distribution. We observed stronger avoidance of open habitat types in the hunting zone than in the non hunting zone for the hartebeest Alcelaphus buselaphus, oribi Ourebia ourebi, roan Hippotragus equines, kob Kobus kob, Waterbuck Kobus ellipsiprymnus defassa and reedbuck Redunca redunca. In contrast, in grey duiker Sylvicapra grimmia, red-flanked duiker Cephalophus rufilatus, bushbuck Tragelaphus scriptus and buffalo Syncerus caffer we found no differences in habitat use between hunted and non-hunted areas. This may indicate that the latter species show more pronounced ecological and behavioural plasticity. Further, resource selection of bovid species on a small scale was influenced by other factors such as habitat structure, landscape characteristics, and human disturbance. This preliminary assessment of bovid habitat relationships in west Africa suggests that human hunting activities may cause species to alter their habitat selection. We therefore suggest habitat models may need to incorporate this source of variation if they are to accurately predict habitat use or distribution of a species.
Journal Article
Actors’ Perceptions of Profitability Along a Bushmeat Commodity Chain in West Africa (Southern Benin)
2024
Background and Research Aims: The bushmeat trade is one of the main drivers of faunal extinction in tropical Africa. We assess the profitability of the bushmeat trade along the commodity chain in southern Benin and study the perceptions of the actors on the profitability of the trade. Methods: Data were collected through direct interviews. A total of 120 bushmeat trade actors were interviewed in southern Benin. Economic and financial indicators were estimated and compared using descriptive statistics. Factors affecting the actors’ perception of wild animal hunting, trading or supply sustainability were assessed using binary logit. Results and discussion: A total of 15 species were traded along the bushmeat commodity chain in southern Benin. During the dry season, hunters’ gross product is higher because of greater hunting effort, and traders earn more commercial margin. Throughout the chain of actors, bushmeat trade profitability is seen as positively affected by the number of hunters per household and the availability of large preys (hunters), household size (sellers) and monthly income (consumers); whereas negative factors affecting profitability are distance from hunting sites (hunters), supply issues (sellers) and the cost of the meat (consumers). Both hunters and consumers see hunting and trade regulation measures as negatively impacting bushmeat profitability. Conclusion and implications for conservation: The perception of profitability by bushmeat commodity chain actors in southern Benin is conditioned by a set of socio-economic factors that should be considered in national conservation policies and development programs to keep bushmeat hunting profitable and sustainable.
Journal Article