Amphibians are experiencing global population declines at a rate substantially higher than that of most other taxa. Because habitat loss and land conversion are primary drivers of this decline, identifying mechanisms that promote species diversity and abundance in agricultural landscapes is a critical component of species conservation. This is particularly germane to tropical regions, where amphibian diversity as well as rates of species loss and forest conversion are higher than average. In Puerto Rico, eleven of the sixteen species of native Eleutherodactylus (coqui) frogs are found in coffee growing areas, of those, nine occur nowhere else, and seven are endangered. As much of the land on the island has already been converted to agriculture, conservation efforts must also consider these altered ecosystems. Not all agricultural systems have equal conservation potential however. Variation in planned vegetation diversity, shade level and pesticide application can impact biodiversity levels. This study was conducted on twenty-nine coffee farms and investigated how coquis use available vegetation for both shelter and foraging. Coquis were located after dark to gather activity data, and during the day to determine shelter selection. On each farm, vegetation surveys were carried random points and locations at which coquis were found.
Results/Conclusions
Preliminary results show significant variation in coffee farm vegetation use by coquis. An important aspect of management appears to be both the presence and maintenance of plantains on coffee farms. During the day, 69% of 149 sheltering coquis found were in plantains, 13% were located in coffee plants, and the remaining 18% were spread across six other vegetation types or substrates. In the evening, only 35% of 153 active coquis found were on plantains, while 37% were found on coffee. This is important in that individual coqui have been shown to consume substantial quantities of arthropods throughout a night, and the movement from plantain to coffee after dark could potentially allow for the consumption of nocturnal coffee pests. Regarding plantain maintenance, another important finding is that the removal of dry, curled, plantain leaves that remain attached to the trunk significantly shifts daytime sheltering from plantain to coffee, however the number of coqui found at sites with cleaned plantains dropped to 71 individuals, compared to 174 observations at untrimmed sites. Additionally, of the ten times that coqui reproduction was found, either eggs or recent hatchlings, nine were located in dry, curled, plantain leaves.