Munroe Revisited: A Survey of West Indian Butterfly Faunas and Their Species-Area Relationship

The latest butterfly species numbers for sixty-seven West Indian islands and South Florida are presented. Estimating the species richness of insular faunas is rarely straightforward and the difficulties are discussed in the context of West Indian butterflies. The data are considered minimum estimates because the number of species overlooked is still likely to exceed the number of vagrant and extinct species accidentally included. With this caveat in mind, the species-area relationship is examined. The correlation between island area and species richness was first described for West Indian butterflies by Eugene Munroe in 1948. Despite an additional fifty-seven data points, today's species-area regression (slope, z = 0.20; intercept, c = 1.06) is not significantly different from that observed in 1948 (z = 0.26; c = 0.80). To our knowledge, butterflies have the flattest species-area regression reported for any West Indian taxon. The possible implications of the species-area relationship for the biogeography of West Indian butterflies are discussed.