The frogs of Puerto Rico are obvious in virtually all habitats (Schmidt 1928; Drewry 1970a,c; Odum et al. 1970c; Rivero 1978). Except for the islandwide Leptodactylus albilabris, all eleven native species in the forest are members of the genus Eleutherodactylus (table 8.1, fig.8.1) Eleutherodactylus coqui Thomas is the widespread generalist of Puerto Rico and is present in all but the driest parts of the island. Most of the other species are restricted in range and in habitat, primarily at higher altitudes in the Luquillo Experimental Forest. Densities of Eleutherodactylus in Puerto Rico and Jamaica are the highest recorded so far for frogs anywhere (see Population Structure), although comparisons with species that aggregate for breeding are difficult. Wolcott (1924) mentioned the abundance of coquis in Puerto Rico but did not recognize their importance as predators; he still suggested that one needed the large introduced Bufo agua (=B.marinus) for effective insect control.

We summarize available information on the role of Eleutherodactylus in the Luquillo Experimental Forest as a major pahtway of energy flow through the system. We present a comprehensive study of the diet of the abundant coqui, E. coqui, along with data on the diets of other common species, and we compile a list of known frog predators from field observations. We evaluate the importance of frogs to the forest ecosystem in term is of biomass and numbers of prey harvested by coquis and the number of coquis harvested by predators. We also estimate energy intake and expenditure by adult coquis.