Javier A. Rodríguez - Abstract #9

Abstract

10. Rodríguez-Robles, J. A., and H. W. Greene. 1996. Ecological patterns in Greater Antillean macrostomatan snake assemblages, with comments on body-size evolution in Epicrates (Boidae), pp. 339-357. In: Contributions to West Indian Herpetology: A Tribute to Albert Schwartz (R. Powell and R. W. Henderson, eds.). Contributions to Herpetology, Volume 12. Society for the Study of Amphibians and Reptiles, Ithaca, New York.

Fifty-one species of macrostamatans snakes inhabit the Greater Antilles; 32 species are small, 11 are of medium size, and eight are large. Small and medium-sized- Greater Antillean macrostomatans prey mainly or entirely on lizards and frogs, whereas six of the seven large species for which dietary data are available primarily eat mammals. Several colubrid clades have diversified on the four largest Greater Antillean islands, and macrostomatan species richness is positively correlated with island area. Only Cuba supports more than one species of Tropidophis and on that island one species eats birds and mammals with some frequency, whereas the other nine prey mostly on lizards and frogs; perhaps they have diversified mainly in terms of habitats. No island supports more than one large specialist on mammals (i.e. Epicrates); on islands with more than one species of Epicrates, the additional species is (are) smaller and feeds predominantly on lizards when adult. The genus Epicrates includes six large, robust species and four smaller, more slender species. Phylogenetic analyses suggest that size reduction has occurred in the mainland E. cenchria and twice within the Antillean clade, whereas size increase has occurred in E. angulifer. The hypothesis that a shift to an adult diet of lizard prey was a likely factor in the evolution smaller body length in Caribbean Epicrates is supported by a phylogenetic analyses of the evolution of this character. Antillean macrostomatan snakes offer rich opportunities for studying historical and contemporary ecological phenomena, but to realize fully that potential we need much additional information on their natural history and phylogenetic relationships.