My primary interests lie in population and evolutionary ecology, and in molecular systematics, phylogeography (the study of the geographical distribution of genealogical lineages, especially those of intraspecific populations), and biogeography of reptiles and amphibians. My ongoing research projects include:

• Feeding ecology of the Speckled Rattlesnake, Crotalus mitchellii, and the Coachwhip, Masticophis flagellum (with Xavier Glaudas)
• Hybridization genetics of the Puerto Rican Grass Anole, Anolis pulchellus (with Tereza Jezkova and Manuel Leal)
• Comparative phylogeography of the White-lipped Frog (Leptodactylus albilabris), the Green Anole (Anolis evermanni), and the Yellow-chinned Anole (Anolis gundlachi) (with Tereza Jezkova and Viktoria Hemmings)
• Genetic divergence in the boa Epicrates monensis and the Puerto Rican Racer, Borikenophis portoricensis (with Miguel A. García)
• Origin of rattlesnakes (Crotalus and Sistrurus): molecular phylogenetic tests of alternative hypotheses (with Kelly R. Zamudio, Harry W. Greene, David M. Hillis, and Jonathan A. Campbell) (See Evolution and biogeography of rattlesnakes)