Interactions between branchiate mole salamanders (Ambystoma talpoideum) and lesser sirens (Siren intermedia): asymmetrical competition and intraguildpredation

Using field sampling and experiments in natural and artificial ponds, I stu died interactions between branchiate adult mole salamanders (Ambystoma talp oideum) and lesser sirens (Siren intermedia), two top predators in temporar y ponds of the southeastern United States. The abundance and distribution o f these two salamanders were independent among ponds, with A. talpoideum mo re numerous and widespread than S. intermedia. Both species were more likel y to be found in ponds near other intermittent wetlands. Within a pond, cap tures of these two species were negatively correlated, and a held experimen t showed that paedomorphic A. talpoideum avoided traps containing S. interm edia. An experiment in artificial ponds confirmed that interactions between these two species were highly asymmetrical; S. intermedia reduced the grow th and recruitment of A. talpoideum without experiencing reciprocal, positi ve or negative effects. These results suggest that S. intermedia competes w ith and is an intraguild predator of A. talpoideum, limiting its growth and controlling its recruitment.