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Di Vittorio M.,Ecologia Applicata Italia srl | Luiselli L.,Environmental Studies Center Demetra | Luiselli L.,Rivers State University of Science And Technology
Ardeola | Year: 2015

The presence of the lanner falcon Falco biarmicus feldeggi in Sicily was modelled by generalized linear models using climatic, topographic, ecological and land-use variables at both the landscape (UTM cells of 10 × 10 km) and the home range (12.56 km2) spatial scales. At the landscape scale, a significant spatial autocorrelation of the lanner population, corresponding to the longitudinal distribution of sites, was found, with the species occurring within the most xeric UTM cells. There was also a negative relationship between falcon presence and potential evapo-transpiration values, either in the coldest months or throughout the year. The same negative relationship was also seen with the surfaces of CORINE artificial areas, thus showing that the species has a low tolerance to any anthropogenic landscape. At home range scale, our predictive models revealed a preference for territories with steep slopes surrounded by natural grassland, sclerophyll vegetation, arable land and agricultural land. The lack of spatial correlation and the identification of specific preferred land use classes, suggests that the home range scale is more appropriate than the landscape scale for predicting the occurrence of lanner falcons. The maintenance of a stable lanner falcon population in Sicily should be addressed at both small and large scales. Source


Akani G.C.,Rivers State University of Science And Technology | Eniang E.A.,University of Uyo | Petrozzi F.,Rivers State University of Science And Technology | Petrozzi F.,Ecologia Applicata Italia srl | And 3 more authors.
Amphibia Reptilia | Year: 2014

Niche partititioning patterns have not been studied so far in burrowing tropical snakes of the families Typhlopidae and Leptotyphlopidae. In this study, we analyze temporal (= monthly activity) and spatial (= habitat use) niche dimensions in three species of burrowing snakes from the Niger Delta, Nigeria. Null model analyses, using two randomization algorithms and 30 000 Monte Carlo permutations, showed that there was random resource partitioning patterns as for the spatial niche dimension. One species (Rhinotyphlops punctatus) clearly dominated in the sample, and appeared to be more habitat generalist than the others. All three species showed an uneven monthly activity, with peaks occurring by wet season, and statistically significant positive correlations between mean monthly rainfall and number of captured snakes. However, there were significantly negative correlations between mean monthly temperature and number of captured snakes in two of the three species (Rhinotyphlops congestus; Leptotyphlops cfr. sundewalli). © Copyright 2014 by Koninklijke Brill NV, Leiden, The Netherlands. Source


Akani G.C.,Rivers State University of Science And Technology | Aifesehi P.E.E.,University of Port Harcourt | Petrozzi F.,Rivers State University of Science And Technology | Petrozzi F.,Ecologia Applicata Italia srl | And 3 more authors.
Tropical Zoology | Year: 2014

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. © 2014 Istituto per lo Studio degli Ecosistemi of the Consiglio Nazionale delle Ricerche, Firenze. Source


Akani G.C.,Rivers State University of Science And Technology | Aifesehi P.E.E.,University of Port Harcourt | Petrozzi F.,Rivers State University of Science And Technology | Petrozzi F.,Ecologia Applicata Italia srl | And 3 more authors.
Vie et Milieu | Year: 2014

The Taylor Creek Forest reserve (Bayelsa State) is one of the most important protected areas of the River Niger Delta region, southern Nigeria. Unfortunately, however, no field studies are available on the diversity of the terrestrial vertebrates (amphibians, reptiles, mammals) in this protected territory. Here, we report the results of field surveys devoted to assess on a preliminary base the vertebrate diversity of Taylor Creek Forest reserve. Mammals and amphibians were assessed only qualitatively, whereas reptiles were assessed also quantitatively within 15 plots of 2 ha area. We detected about 70 vertebrate species (some genera may include multiple species that remained non-detected in our surveys). Several of the recorded species were of high conservation concern (e.g. manatee, dwarf crocodile, hinge-back tortoises, etc.). The presence of the endangered Nigerian chimpanzee was suspected for the Forest Reserve, and indeed few groups of this species do occur in the surroundings of the protected area. Analysis of the reptile diversity suggested that, however, species dominance was high and evenness was low, with very few lizard species dominating the samples. Thus, the reptile community diversity profile revealed altered ecological conditions in this forest area. The conservation implications of the observed patterns are also discussed. Source


Luiselli L.,Rivers State University of Science And Technology | Luiselli L.,Environmental Studies Center Demetra | Amori G.,National Research Council Italy | Akani G.C.,Rivers State University of Science And Technology | And 2 more authors.
Biodiversity and Conservation | Year: 2015

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. Twenty-one 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 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. © 2015, Springer Science+Business Media Dordrecht. Source

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