Morphological and Dietary Structuring of a Zambian Insectivorous Bat Community

Diet and external morphology of nine species of insectivorous bats from Zambia, East Africa, were compared using multivariate methods. Morphological and dietary resemblance between species were positively correlated; that is, taxa which resembled each other most strongly morphologically were also most similar in dietary intake. The degree of morphological and dietary distinctiveness of a species was positively correlated with its morphological and dietary variability. For example, species which are quite distinct from others in morphology or diet tend also to be quite variable in those two attributes. Morphology of the bats was strongly predictive of their diets; most dietary variance was accounted for by morphological variance, and the first morphological principal component predicted the presence in the diet of Lepidoptera, beetles, and Orthoptera with a high level of significance. These results led to a model of community organization for closely related species in which a relatively large number of specialists with invariant attributes are clustered near the community centroid and a smaller number of distinctive, variable species occupy niches more distant from the centroid.