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

Using field sampling and experiments in natural and artificial ponds, I studied interactions between branchiate adult mole salamanders (Ambystoma talpoideum) and lesser sirens (Siren intermedia), two top predators in temporary ponds of the southeastern United States. The abundance and distribution of these two salamanders were independent among ponds, with A. talpoideum more numerous and widespread than S. intermedia. Both species were more likely to be found in ponds near other intermittent wetlands. Within a pond, captures of these two species were negatively correlated, and a held experiment showed that paedomorphic A. talpoideum avoided traps containing S. intermedia. An experiment in artificial ponds confirmed that interactions between these two species were highly asymmetrical; S. intermedia reduced the growth and recruitment of A. talpoideum without experiencing reciprocal, positive or negative effects. These results suggest that S. intermedia competes with and is an intraguild predator of A. talpoideum, limiting its growth and controlling its recruitment.