[1] CNRS, Theoret & Expt Ecol SETE, 2 Route CNRS, F-09200 Moulis, France
[2] Univ Montpellier, Univ Paul Valery Montpellier 3, CEFE, IRD,CNRS,EPHE, F-34095 Montpellier, France
[3] Utah State Univ, Dept Biol, Logan, UT 84322 USA
[4] Univ Montpellier, CNRS, ISEM, IRD,EPHE, F-34095 Montpellier, France
[5] Univ Notre Dame, Dept Biol Sci, South Bend, IN 46556 USA