MAPPING BIODIVERSITY USING SURROGATES FOR SPECIES RICHNESS - MACRO-SCALES AND NEW-WORLD BIRDS

A number of surrogates have been suggested for predicting relative lev els of biodiversity (typically expressed in terms of species richness) in areas for which this information is not available. However, to dat e there has been little attempt to perform direct and explicit empiric al comparisons of their effectiveness. Here we examine the relative pr edictive value of some environmental variables and of the numbers of h igher taxa, using the avifauna of the New World. Numbers of genera and families are found to have the strongest correlations with species ri chness, and to provide the best predictions of the numbers of species in areas of Central and South America on the basis of data for North A merica. Their effectiveness as surrogates may result from the fact tha t they themselves represent an alternative currency for expressing lev els of biodiversity.