Assessing the spatiotemporal dynamics of endangered mammals through local ecological knowledge combined with direct evidence : the case of pangolins in Benin (West Africa)

Although pangolins are considered to be one of the most trafficked wild mammals in the world, their conservation status remains uncertain through most of their ranges, and notably in western Africa. Using local ecological knowledge in combination with direct occurrence evidence, we assessed the distribution and abundance of the white-bellied pangolin (Phataginus tricuspis) and the giant pangolin (Smutsia gigantea) in Benin over the last two decades (1998-2018). We organised focus groups with local hunters in 312 villages within sampling units of 25 km × 25 km covering the whole country. Participatory maps of past and current geographic ranges of pangolins combined with direct evidence (96 collected scales) suggested that the white-bellied pangolin had a wide distribution and reached higher latitudes than previously known, whereas the giant pangolin could be restricted to a single forest and has been absent from the northern part of the country over at least the last two decades. Local hunters perceived a significant decline of the white-bellied pangolin (range contraction = 31% in 20 years) and almost unanimously an extirpation of the giant pangolin (93%), the latter being restricted to the Alibori forest reserve (northern Benin). Protected areas were identified as the main potential occurrence zones for pangolins: 77 and 100% of the potential geographic ranges of the white-bellied and the giant pangolins, respectively, overlapped partially or totally with the protected area network of Benin. Using a generalized linear model, we showed that the probability of reporting recent observations of the white-bellied pangolin was significantly higher for villages near protected areas and distant from main roads. The forests perceived as having sustainable populations of white-bellied pangolins were the Lama Forest reserve (southern Benin) and the complex comprising Monts Kouffé - Wari Maro - Ouémé supérieur (central Benin), a view that was supported by the great number of direct occurrence evidence collected in those areas. Overall, our study highlights an important geographic range contraction of the white-bellied pangolin and a possible entire extirpation of the giant pangolin over the last two decades in Benin

Modeling population extirpation rates of white‐bellied and giant pangolins in Benin using validated local ecological knowledge

Abstract 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

Can DNA help trace the local trade of pangolins? Conservation genetics of white-bellied pangolins from the Dahomey Gap (West Africa)

International audienceAbstract 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 (\textless 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