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dc.contributor.authorWilson, J.W.
dc.contributor.authorvan Rensburg, B.J.
dc.contributor.authorFerguson, J.W.H.
dc.contributor.authorKeith, M.
dc.date.accessioned2008-03-14T10:13:59Z
dc.date.available2008-03-14T10:13:59Z
dc.date.issued2008
dc.identifier.issn0305-0270en
dc.identifier.urihttp://hdl.handle.net/123456789/328
dc.description.abstractAim To assess the relative importance of environmental (climate, habitat heterogeneity and topography), human (population density, economic prosperity and land transformation) and spatial (autocorrelation) influences, and the interactions between the above-mentioned predictor groups, on species richness patterns of various avifaunal orders. Location South Africa. Methods Generalised linear models were used to determine the amount of variation in species richness, for each order, attributable to each of the different predictor groups. To assess the relationships between species richness and the various predictor groups, a deviance statistic (a measure of goodness of fit for each model) and the percentage deviation explained for the best fitting model were calculated. Results Of the 12 avifaunal orders examined, spatially structured environmental deviance accounted for most of the variation in species richness in 11 orders (averaging 28%) and 50% or more in seven orders. However, orders comprising mostly water birds (Charadriiformes, Anseriformes, Ciconiformes) had a relatively large component of purely spatial deviance compared with spatially structured environmental deviance, and much of this spatial deviance was due to higher order spatial effects, such as patchiness, as opposed to linear gradients in species richness. Although human activity, in general, offered little explanatory power to species richness patterns, it was an important correlate of spatial variation in species of Charadriiformes and Anseriformes. The species richness of these water birds was positively related to the presence of artificial water bodies. Main conclusions Not all bird orders showed similar trends when assessing, simultaneously, the relative importance of environmental, human and spatial influences in affecting bird species richness patterns. Although spatially structured environmental deviance described most of the variation in bird species richness, the explanatory power of purely spatial deviance, mostly due to nonlinear geographical effects such as patchiness, became more apparent in orders representing water birds. This was especially true for Charadriiformes, where the strong anthropogenic relationship has negative implications for the successful conservation of this group.en
dc.description.sponsorshipThe Avian Demography Unit, University of Cape Town provided bird distribution data, while the National Research Foundation and the University of Pretoria provided financial support. BJVR acknowledges support from the DST-NRF Centre of Excellence for Invasion Biology.en
dc.format.extent512728 bytes
dc.format.mimetypeapplication/pdf
dc.language.isoenen
dc.publisherBlackwell Publishing Ltden
dc.subjectavifaunal ordersen
dc.subjectenvironmental factorsen
dc.subjecthuman activitiesen
dc.subjectmacroecologyen
dc.subjectspatial autocorrelationen
dc.subjectwater birdsen
dc.subjectSouth Africaen
dc.titleThe relative importance of environment, human activity and space in explaining species richness of South African bird ordersen
dc.typeJournal Articlesen
dc.cibjournalJournal of Biogeographyen
dc.cibprojectLarge-scale patterns in diversityen


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