Measures of species diversity in ecology: an evaluation

Twenty-four measures of species diversity, richness and equitability were c ompared using both real species abundance data (bird censuses on a standard study plot) and simple simulation tests. Based on 20 criteria, the most re commendable measures for the estimation of alpha diversity of species have been Fager's "number of moves per specimen", exponential Shannon's informat ion (or H'), reciprocal Simpson's lambda, and species richness (number of s pecies). However. the last index is only appropriate when sample sizes are approximately equal otherwise it can be misleading and Hurlbert's rarefacti on method should be applied. The other measures tested, especially all equi tability indices, have been shown to be problematic and should not be used regularly for the measurement of species diversity.