The world’s biogeographical regions: cluster analyses based on bat distributions

13 October 2010

Aim: Both floral kingdoms and faunal regions have so far been intuitively defined. This study was conducted to compare these with an analytical regionalization based on cluster analyses in a fairly homogeneous, globally distributed group of organisms: the bats (order Chiroptera). This comparison was used to discuss the possibilities of employing clustering techniques in global biogeography. Location: The study considered bat distributions world-wide. Methods: Analyses were conducted both for presence/absence of genera and species, and for the number of species in each genus. Clusters distinguished at selected dissimilarity values were mapped. Results: A set of c. 10 regional clusters recurred in the analyses, broadly corresponding not only to the world’s accepted faunal regions and subregions, but also to the floral kingdoms and subkingdoms. Main conclusions: This study is an analytical confirmation of the fact that similar global distribution patterns are to be found in different groups of organisms. Cluster analyses can be used to refine global regionalization schemes, and, with the accumulation of such data for different taxa and ecologically defined groups, shared patterns can be used to draft one common global biogeographical regionalization. At the same time, differences between the regionalization schemes derived for different groups can be used to partial out the role of dispersal abilities, body size, evolutionary age, etc., in determining global distribution patterns.