1. Institute of Ecology, Vilnius University, Akademijos 2, Vilnius 21, LT-08412, Lithuania
2. Center for Tropical Research, Institute of the Environment, University of California, Los Angeles, 1365 Hershey Hall, P.O. Box 95 1496, Los Angeles, California 90095-1496, USA
3. Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, California, 94132, USA
4. Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California 90095-1606, USA