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5 result(s) for "White-bellied pangolin"
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Conservation genetics of the white‐bellied pangolin in West Africa: A story of lineage admixture, declining demography, and wide sourcing by urban bushmeat markets
During the last 40 years, the volumes of African pangolins feeding the illegal wildlife trade have dramatically increased. We conducted a conservation genetics survey of the most traded African species, the white bellied pangolin (WBP; Phataginus tricuspis), across three West African countries including Guinea, Côte d'Ivoire, and Ghana. Our study combining mitochondrial DNA sequencing and microsatellite genotyping is the first to reveal a wide pattern of admixture between two of the six mitochondrial lineages as previously delimited within WBP. We found a signature of isolation by distance but a lack of population genetic structuring, supporting the idea that WBP may have underestimated dispersal abilities. Levels of genetic diversity were low in West African lineages (WAfr and Gha) compared to Central Africa, reinforcing the picture of genetic pauperization shared by West African WBP. We observed a 85%–98% decline in the effective population size of WBP occurring c. 3200 to 400 ya, with current numbers (520–590) at the lower end of the conservative thresholds for minimum viable population size. The microsatellite markers were powerful enough to differentiate between individuals and identify replicated samples, confirming the utility of this approach in tracing the pangolin trade. Genetic diversity estimates confirmed that Yopougon, the main bushmeat market from Abidjan (Côte d'Ivoire), was fed by a large trade network as confirmed by vendors reporting 10 different sources situated 62–459 km away from the market. We conclude that WBP distributed in the Upper Guinean Block should be considered a single management unit of high conservation concern, as impacted by genetic diversity erosion, drastic decline in effective population size, and wide range sourcing for feeding urban bushmeat markets. Given the genetic admixture pattern detected within WBP from West Africa, we advocate for a multi‐locus strategy to trace the international trade of the species. Résumé Au cours des 40 dernières années, les volumes de pangolins africains alimentant le commerce illégal d'espèces sauvages ont augmenté de façon spectaculaire. Nous avons mené une étude de génétique de la conservation sur l'espèce africaine la plus braconnée, le pangolin à ventre blanc (PVB; Phataginus tricuspis), à travers trois pays d'Afrique de l'Ouest incluant la Guinée, la Côte d'Ivoire et le Ghana. Notre étude combinant le séquençage de l'ADN mitochondrial et le génotypage par microsatellites est la première à révéler un patron généralisé d'admixture entre deux des six lignées mitochondriales précédemment délimitées au sein du PVB. Nous mettons en évidence une signature d'isolement par la distance mais un manque de structuration génétique des populations, soutenant l'idée que le PVB a des capacités de dispersion jusque‐là sous‐estimées. Les niveaux de diversité génétique observés dans les lignées d'Afrique de l'Ouest (WAfr et Gha) sont faibles par rapport à ceux observés en Afrique Centrale, confirmant la paupérisation génétique des populations de PVB en Afrique de l'Ouest. Nous avons observé un déclin de 85 à 98% de la taille efficace de la population ouest‐africaine entre 3200 et 400 ans, les estimations actuelles (520–590) se situant à l'extrémité inférieure des seuils minimums de viabilité. Les marqueurs microsatellites utilisés sont suffisamment puissants pour différencier les individus et identifier les doublons d'échantillons, confirmant l'utilité de ces marqueurs pour tracer le commerce des pangolins. Nos estimations de diversité génétique ont confirmé que Yopougon, le principal marché de viande de brousse d'Abidjan (Côte d'Ivoire), était alimenté par un vaste réseau commercial, comme le confirment les vendeurs signalant 10 sources différentes situées à 62–459 km du marché. Nous concluons que les PVB présents dans le bloc forestier de Haute Guinée devraient être considérés comme une seule unité de gestion à fort intérêt de conservation, étant soumis à une érosion de sa diversité génétique, un déclin drastique de la taille efficace de sa population et un approvisionnement à grande échelle des marchés urbains de viande de brousse. Compte tenu du schéma d'admixture génétique détecté chez les PVB d'Afrique de l'Ouest, nous préconisons une stratégie multi‐locus pour tracer le commerce international de l'espèce. Our work derives from an unprecedented, exhaustive genetic survey of the pangolin trade in three countries from West Africa (Guinea, Cote d'Ivoire, and Ghana). Our study combining mitochondrial DNA sequencing and microsatellite genotyping is the first to reveal a global pattern of admixture between two of the six mitochondrial lineages previously delimited within the white‐bellied pangolin (WBP).
Genetic tracing of the illegal trade of the white-bellied pangolin (Phataginus tricuspis) in western Central Africa
The white-bellied pangolin is subject to intense trafficking, feeding both local and international trade networks. In order to assess its population genetics and trace its domestic trade, we genotyped 562 pangolins from local to large bushmeat markets in western central Africa. We show that the two lineages described from the study region (WCA and Gab) were overlapping in ranges, with limited introgression in southern Cameroon. There was a lack of genetic differentiation across WCA and a significant signature of isolation-by-distance possibly due to unsuspected dispersal capacities involving a Wahlund effect. We detected a c. 74.1–82.5% decline in the effective population size of WCA during the Middle Holocene. Private allele frequency tracing approach indicated up to 600 km sourcing distance by large urban markets from Cameroon, including Equatorial Guinea. The 20 species-specific microsatellite loci provided individual-level genotyping resolution and should be considered as valuable resources for future forensic applications. Because admixture was detected between lineages, we recommend a multi-locus approach for tracing the pangolin trade. The Yaoundé market was the main hub of the trade in the region, and thus should receive specific monitoring to mitigate pangolins’ domestic trafficking. Our study also highlighted the weak implementation of CITES regulations at European borders.
Can DNA help trace the local trade of pangolins? Conservation genetics of white-bellied pangolins from the Dahomey Gap (West Africa)
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.
Habitat Suitability Modelling of White-Bellied Pangolin (Phataginus tricuspis) in Oluwa Forest Reserve, Ondo State, Nigeria
Most endangered species face a significant threat from habitat loss. The destruction and degradation of natural tropical forest across West Africa has likely been the biggest threat to White-bellied Pangolin and has contributed to their decline as they depend on the habitat for different resources like food, water, and shelter. The current study investigated the habitat suitability of white-bellied pangolins in Oluwa Forest Reserve. The presence data of White-bellied pangolin was collected by taking the Global Positioning System (GPS) coordinates of the indirect signs observed. These data, along with the 19 bioclimatic variables, slopes, soil PH, soil texture, distance to rivers, distance to roads, and Normalized Difference Vegetation Index (NDVI), were used to generate habitat suitability maps using MaxEnt software. The MaxEnt analysis showed that out of 781 km available for White bellied Pangolin during dry season, 338 km was highly suitable, 209 km was suitable, 126 km was moderately suitable, 65 km was less suitable and 44 km was not suitable. During the wet season 235 km was highly suitable, 225 km was suitable, 164 km was moderately suitable, 100 km was less suitable and 57 km was not suitable habitat. The jackknife test of variable contribution revealed that during the dry season, NDVI was the most important predictor variable as measured by the gain produced by a one-variable model, followed by aspects such as distance to the river, slope, distance to the road, and temperature seasonality. During the wet season, the jackknife-cross-validation test showed the highest gain when NDVI was used in isolation. Aspects were found to be the second most important predictor variable as measured by the gain produced by a one-variable model, followed by distance to the road, slope, elevation, and the mean temperature of the wettest quarter.
COMPLICATIONS ASSOCIATED WITH PREGNANCY AND PARTURITION IN AFRICAN WHITE-BELLIED PANGOLINS (PHATAGINUS TRICUSPIS)
There are no studies to date on the normal reproductive physiology of African white-bellied pangolins (Phataginus tricuspis). As a reclusive species, little is known about normal gestation, successful parturition, and potential complications during pregnancy. Ten female P. tricuspis were diagnosed as pregnant and monitored under professional care. Five developed complications during pregnancies or during parturition and are detailed in this case series. Dystocia occurred in two dams each, with malposition of a singleton fetus. Both dams were successfully treated with surgical intervention by caesarian section. Of the two individuals, one fetus was nonviable, but the other neonate survived and was reared by the dam to weaning. A third pregnant female died during pregnancy from septicemia resulting in death of the preterm fetus. The two additional dams of the five gave birth to full-term neonates. One fetus was stillborn with evidence of fetal distress, and the other died immediately after birth (perinatal death) with undetermined etiology. Based on this case series, complications associated with pregnancy occur in P. tricuspis, indicating the need for further study and close monitoring during impending parturition.