A long-term ecological survey of bats (Mammalia, Chiroptera) in the eastern Niger Delta (Nigeria)

The structure of bat assemblages was studied in relation to variation in forest landscapes in four localities of the eastern Niger Delta (southern Nigeria). The study areas were inhabited by thirteen species, seven Megachiroptera and six Microchiroptera, among which Eidolon helvum, Hypsignathus monstrosus, Rousettus egyptiacus, Saccolaimus peli, and Hipposideros caffer were recorded for the first time, whereas Epomophorus gambianus, Scotonycteris zenkeri, Megaloglossus woermanni, Scotophilus viridis, and Mops thersites were first cited only recently. The majority of captures occurred in secondary forest habitat (99 specimens belonging to 10 species), followed by primary forest (40 specimens, 5 species), and by the bush (13 specimens, 5 species). A multivariate set of analyses arranged the various species into six 'ecological groups': (i) Eidolon helvum, Mops thersites; (ii) Hipposideros caffer, (iii) Hypsignathus monstrosus; (iv) Rousettus egyptiacus, Epomops franqueti, Scotonycteris zenkeri, Nycteris arge, (v) Saccolaimus peli, Scotophilus viridis,Nycteris hispida; (vi) Epomophorus gambianus, Megaloglossus woermanni. The various groups are interpreted in the light of the available information on the ecology and distribution of Nigerian bats.