Document: JOH-3-52-14

In search of keystone predators: An experimental test of a field method.

FAUTH, J.E.*

University of Charleston, Charleston, SC 29424 USA ¹

Abstract:
Keystone species maintain diversity in their communities. Yet despite their importance, few methods have been suggested to identify keystone predators in species-rich natural communities. I experimentally tested one method that relies on field sampling. This survey method suggested that only the mole salamander (Ambystoma talpoideum) was a keystone predator in temporary ponds of the Francis Marion National Forest, SC. Experiments in artificial ponds with five potential keystone predators showed that A. talpoideum was the strongest keystone, but two other salamanders (eastern newt: Notophthalmus viridescens, and lesser siren: Siren intermedia) also were keystone predators of larval anurans. However, keystone function was independent of initial tadpole density. These results suggest that the field method has difficulty identifying weak or functionally redundant keystone species. It also suggests that all medium-sized aquatic salamanders may be keystone predators, providing functional redundancy in natural systems.

Keywords: keystone species, amphibians, temporary ponds

This abstract is being presented at: 11:45 AM in session:
Oral Session #38: Amphibian Ecology.