Print PageEleutherodactylus coqui is a small tropical terrestrial frog that is native to Puerto Rico and was first seen on the Hawaiian Islands in the late 1980s. Millions of dollars have been spent in recent years in an attempt to control E. coqui, but eradication is deemed no longer possible on the Island of Hawaii. Based on preliminary research suggesting a positive relationship between prey, structure, and E. coqui density in Hawaii, we hypthesized that the success of E. coqui (measured by its density) is positively related to resource availability in the form of structure and prey because structure provides the male with more calling sites, and thus more opportunity to mate with females, and prey provides E. coqui with the necessary energy to reproduce, grow, and increase in density. We designed and conducted a large-scale experiment in the Nanawale Forest Reserve in the southeast region of the Island of Hawaii for 6 months to test this relationship.
Results/Conclusions
E. coqui density was reduced in the 100% leaf litter removal and 100% structure removal treatment plots. E. coqui were observed at lower heights off the forest floor in the 100% structure removal plots than the control plots. Higher quantity of flying and leaf litter invertebrates were found in the 100% structure removal treatment, suggesting a reduction in predation pressure on these invertebrates due to a reduction in coqui frogs. Our results provide a better understanding of the role that specific resources play for the density of an invasive frog in Hawaii. Efforts to efficiently control E. coqui should focus on structure removal and leaf litter removal in areas with large populations of E. coqui.
