1. Department of Ecology & Evolutionary Biology; University of California; 621 Charles E. Young Dr. South Los Angeles California 90095 USA
2. Laboratoire d'Ethologie Expérimentale et Comparée E.A. 4443 (LEEC); Université Paris 13; Sorbonne Paris Cité 99 Av. J.B. Clément F-93430 Villetaneuse France
3. Department of Animal Physiology; University of Bayreuth; Universitätsstrasse 30 D-95440 Bayreuth Germany
4. The Rocky Mountain Biological Laboratory; Box 519 Crested Butte Colorado 81224 USA