Nioking Amadi

Are mammal communities occurring at a regional scale reliably represented in “hub” bushmeat markets? A case study with Bayelsa State (Niger Delta, Nigeria)

Abstract. Monitoring of bushmeat markets has traditionally been seen as a source of faunistic and ecological data on mammal communities in West Africa. Nonetheless, it is largely unexplored whether datasets coming from monitoring of large “hub” markets in towns can reliably picture the mammal faunas and community compositions at the local level. Here, Swali market in Bayelsa State, Nigeria, that is one of the largest bushmeat markets in the Niger Delta, was monitored for six months in 2013–2014. Data from Swali market were compared with those collected during regular field surveys at five protected forests situated within 15 km radius from the market. A total of 21 mammal species was recorded at Swali versus 29 in the five protected forests. The trade was more intense by wet season. There was a statistically significant linear relationship between mean weight of the sold mammal and its price. A considerable portion of species that occur at the protected forests did not occur in the market samples, including the very rare species and the smallsized species. However, the abundance in the market of the common species was positively related to their apparent field abundance in the forest reserves. Therefore, it is concluded that large-sized bushmeat markets did not depict reliably the whole faunal composition and the community structure of mammals in West Africa, although these types of surveys are sufficient to characterize the abundance distribution of the common species at the regional scale.

Preliminary surveys of the terrestrial vertebrate fauna (mammals, reptiles, and amphibians) of the Edumanon Forest Reserve, Nigeria

The Edumanon Forest Reserve is one of the least explored protected areas in the Niger Delta region of southern Nigeria, West Africa. In this article, we report the results of preliminary surveys, conducted between 2011 and 2014, for determining a checklist and a relative estimate of abundance for three groups of vertebrates, namely mammals, reptiles, and amphibians. Overall, we detected 69 vertebrate species (birds excluded), several of them being of high conservation concern. Among the most remarkable species from the conservation point of view, we can cite the chimpanzee, the manatee, and three species of sympatric crocodiles. Analysis of the reptile diversity suggested that species dominance was high and evenness was low, thus revealing altered ecological conditions in this forest area. Nonetheless, several forest specialists were still observed in this forest reserve. The conservation implications of the observed patterns, together with some ethnozoological data, are also discussed.

Surveys of mammal communities in a system of five forest reserves suggest an ongoing biotic homogenization process for the Niger Delta (Nigeria)

Community composition and an index of relative abundance were analyzed for mammals (excluding most rodents, shrews and bats) of five forest reserves in the Niger Delta (Southern Nigeria). Twenty-nine species were recorded, 86.2% of them being found in all protected areas. Although most of the species were already known from the study area, there were unexpected patterns concerning the duikers. Indeed, the presence of only one species (Philantomba walteri) (CH Smith, 1827) was confirmed, whereas at least five additional duiker species were reported for the study area by earlier authorities. Another duiker species (Cephalophus niger Gray, 1846) was recorded once during the present surveys and is not known whether it represents a stabilized presence in the Niger Delta. The empirical Abundance Index suggested that only three species were very rare (Trichechus senegalensis (Link, 1795), C. niger, and Pan troglodytes (Blumenbach, 1775)). Diversity-dominance diagrams showed that the evenness profiles were similar across study areas. Linear distance (Km) between the barycenters of forest reserves was significantly positively correlated with relative community composition dissimilarity. Overall, a biotic homogenization process for the mammal communities of the five forest reserves was observed, likely as an outcome of the high deforestation of the last 50 years.

Recent distribution data and conservation status of the leopard (Panthera pardus) in the Niger Delta (Nigeria)

The leopard (Panthera pardus) is increasingly threatened in West Africa, and is apparently very rare and has been driven to extinction across much of Nigeria. In the Niger Delta, where it is considered extremely threatened, with very few sightings in the last decades. In this study we document both direct (skins, footprints, scats, etc.) and indirect (village hunter’s interviews) signs of leopard presence in order to reconstruct leopard presence in the Niger Delta, across the period 2000–2015. Data were combined into three survey periods: 2000–2002, 2006–2008 and 2012–2015, and compared with literature data for 1996–1997. Recent skins were recorded in 2.2–4.3% of the villages (n = 39–62). In addition, the leopard was reported to be present by hunters in another 3.3–10.3% of the villages. Overall, some specific sectors of the Delta were recurrently target of both direct and indirect signs of leopard presence (barrier islands and flood forest along the central axis of the River Niger), but all direct sightings occurred in a few barrier islands. In the Niger Delta, there was no evidence of females with cubs since decades and a few skins were the only direct signs of leopard’s current presence. Our results suggest that leopard populations may be functionally extinct in the Niger Delta, with just a few vagrant individuals, in dispersal and/or hunting, being still found. Barrier island forests are apparently the last vegetation zone of the Delta still potentially inhabited by leopards, and deserve careful managements in the years to come.

Inter-seasonal and inter-habitat variations in the diet of the African fire skink, Lygosoma fernandi, from southern Nigeria

The inter-habitat and inter-seasonal variations in the taxonomic diet composition of the African fire skink, Lygosoma fernandi, one of the largest Scincidae of the Afrotropical regions, were studied by analysis of excrements collected from live individuals that were captured in some areas of the Niger Delta region, southern Nigeria. 22 prey types, mostly arthropods, were found in the diet of this species, with significant differences in prey composition between seasons. Isopoda and Coleoptera dominated in the dietary samples, with very few prey types exclusive of one habitat type and/or season (e.g. Formicidae in dry forest in both seasons and lizards in swamp forest in wet season). Overall, no difference between forest types and seasons was found as for diversity and evenness indices except for that prey diversity was higher in feces collected in the dry forest in dry season, whereas dominance and evenness did not show any significant variation across forest types.