The species-area relationship in bat assemblages of tropical caves

We tested for a relationship between number of bat species and surface area of 20 caves in central Mexico and investigated the role of the habitat div ersity model as an explanation for this relationship. There was a significa nt positive correlation between the logarithm of species richness and the l ogarithm of cave surface area, evidence of a species-area relationship. Our data suggest that roost site diversity, as indicated by spatial variation in relative humidity and presence of avons (conical depressions in cave cei lings) is a cause of the species-area relationship.