Ecological diversity, community structure and conservation of Niger Delta mammals

Abstract

The Niger Delta (southern Nigeria) is a crucial region for biodiversity because it is (i) part of the West African forests hotspot, (ii) under considerable threats because of habitat devastations, and (iii) a minor centre of endemism for many faunal and floral groups. In this paper, we analyze the communities of mammals (excluding bats, shrews and murids) occurring in all vegetation zones of the region, using both original field data (direct sightings of live animals, bushmeat market specimens, skins, skulls, bones, tracks, reliable interviews) collected in 1996-2015 and literature data. We also explore the main drivers of community structure by using a suite of multivariate (cluster) and null models (co-occurrence) analyses, and the conservation consequences of our data. A total of 45 extant species was found; their ecological distribution was uneven across vegetation zones, with flood forest, marsh forest and eastern flank forests housing more species. Although most species were widespread, 33.3 % had narrow ecological preferences. Cluster analysis confirmed that the community composition was (i) similar in habitats that were suspected to derive from pristine flood forests, and that (ii) the mammal assemblages were different in the two sides of the River Niger main axis. The endemic rate was low (4.44 % of the species), with one endemic species for each of the two sides of the Niger Delta. Twentyone species were uncertain to occur in the study area, with a few being extinct (for instance, Choeropsis liberiensis). Co-occurrence models excluded that a competitively structured community of species is assembled in each of the vegetation zones, and cluster Communicated by analyses suggested that biogeographic pressures may be important. 24.4 % of the extant species are globally threatened by IUCN, with one being Endangered (Pan troglodytes) and one Critically Endangered (Piliocolobus epieni). Flood forest and Eastern Flank forest represented the main vegetation zones inhabited by threatened species. In order to preserve the mammal community of the Delta, it is essential to carefully conserve flood and marsh forest patches, but also barrier island forests that still house highly threatened mammal populations.

Wildlife harvesting and bushmeat trade in Rivers State, Nigeria: The resilience of the African civet, Civettictis civetta (Carnivora: Viverridae) and records of rare species

“…The vegetation of the catchment area is not uniform lowland rainforest. It consists of deforested plantationsavannah, flood forest, secondary rainforest, Marsh deltaic forest, Mangrove and barrier islands (Luiselli et al, 2015). The detailed keys of Happold (1987) and Kingdom (1979) were used for the identification of wildlife.…”

Structure and diversity of fish communities in man-made ponds of the Niger Delta (southern Nigeria)

“…The Orashi is a hard whitewater tributary of the Niger and is one of the most important areas for the biodiversity conservation in the region (e.g. see Akani et al 2014;Luiselli et al 2015), with a typical fish community characterised by Nilo-Sudanian savannah species and less forest species (Teugels and Powell 2004). Its waters are less acidic, have higher conductivity, have higher nutrient content and are less transparent than the blackwater tributaries that characterise the eastern portion of the Niger system (i.e.…”

Rapid Assessment of Petroleum Hydrocarbon Contamination in Soils: Spectroscopy Approach

“…Furthermore, the United Nation Environment Programme (UNEP) reported in 2011 that in Ogoniland alone (a small part of the Niger Delta), over 69 sites were heavily contaminated with crude oil (concentration > 139,000 mg/kg) affecting soil, air and water quality criteria and posing a serious human health threat. This, in turn, impacts on the quality of water resources: directly affecting the health of local communities, which are drinking contaminated water [5,6,7], and the aquatic flora and fauna, which is being exterminated [8]. Therefore, urgent attention is needed to clean-up these sites.…”