1. Department of Biological Sciences; University of Alabama; Tuscaloosa AL 35487 U.S.A.
2. Odum School of Ecology; University of Georgia; Athens GA 30602 U.S.A.
3. Savannah River Ecology Laboratory; University of Georgia; Aiken SC 29808 U.S.A.
4. Department of Ecology and Evolutionary Biology; Cornell University; Ithaca NY 14853 U.S.A.
5. Department of Biology and Graduate Program in Ecology Evolution and Environmental Biology; Miami University; Oxford OH 45056 U.S.A.