Climatic effects on a non-native amphibian in Hawaii Island: Survivorship along an elevational gradient

Background/Question/Methods: The response of non-native species to climate change is a major concern and an active area of research in Hawaii. Non-native species, which tend to be habitat generalists, are likely to expand their range under future climate scenarios. This project looks at survivorship of the non-native coqui frog (Eleutherodactylus coqui) along an elevational gradient in Hawaii where temperature and precipitation vary. The Hawaiian islands do not have any native amphibians, but E. coqui is currently well established at lower elevations below 600 m in some areas and densities have been estimated to be >50,000 per hectare and three times as dense than in their native Puerto Rico. Enclosures (1 m x 1 m x 1 m) have been set up at every 150 m in elevation from 550 m to 1,000 m on Hawaii Island. Three different frog densities (1,3,5 frogs per enclosure) are being used to investigate if population expansion or contraction will occur under different climatic conditions.

Results/Conclusions: Preliminary results indicate that survivorship of E. coqui is related to temperature and precipitation. As climate changes, there is the potential for E. coqui to expand its distribution and move into higher elevation forest ecosystems.