Analysis of Cuban treefrog (Osteopilus septentrionalis) predation on native Florida treefrog species

Background/Question/Methods

Globally, native amphibian and reptile populations have been in decline with Florida being the most severely impacted state within in the continental U.S.A. due to its subtropical climate allowing exotic species to proliferate. The Cuban treefrog’s high fecundity and ability to predate on insects and small animals has caused a negative impact on native treefrog species. The objective of this study is to determine the effects of predation on the native Florida treefrogs from the invasive Cuban treefrog. Moreover, we will investigate the habitat preference of the Cuban treefrog as it relates to available water sources. Using PVC pipes set up in the FAU preserve, a xeric (dry) habitat, as well as Jonathan Dickinson State Park, a mesic (wet) habitat, we will monitor native and exotic treefrog populations.  We hypothesize that Cuban treefrogs will be most abundant in areas of greater water availability, and predation rates on natives will be highest within mesic habitats. It is important to understand whether the Cuban treefrog is outcompeting the native Florida treefrogs for territory and food and/or significantly predating on native species.

Results/Conclusions

The overall population trend for Cuban treefrogs to predate on other treefrogs is relatively low at just 5.92% but when isolating the larger individuals, sexually mature females, which compromise a smaller population size the rate of frog predation increases to 14.55% which accounts for a larger portion of their selection. This trend could have negative implications for native Florida treefrogs within southern habitats which are conducive to the Cuban treefrogs growth rate as it has been observed that the females within the population grow to larger sizes in warmer climate conditions such as the central and southern most portions of Florida.