Influence of priority effects and pond location on invaded larval amphibian communities

In Florida, the Cuban Treefrog (Osteopilus septentrionalis) is a superb colonist and appears to be a significant driver of amphibian community dynamics. Decline of native anurans has been linked to possible competition with adult O. septentrionalis but interactions during the larval stage are largely unknown. Rearing O. septentrionalis tadpoles along with two native anurans, the Squirrel Treefrog (Hyla squirella) and the Southern Toad (Bufo terrestris) in both experimental artificial ponds and laboratory aquaria, the role of competition as the mechanism driving the dynamics of invaded amphibian communities in Florida was examined. Also examined was the role of priority effects and variation between pond locations in altering interactions between O. septentrionalis and native anuran larvae. Interspecific competition was strong during the larval stage; the presence of O. septentrionalis reduced larval performance and survival of native anurans. Pond location alone had little effect on interspecific interactions, but priority effects were strong. Pond location and priority effects acted together to influence species interactions. The selective influence of different interaction modifiers acted to increase or decrease the impacts of exotic species on native taxa.