1. Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, Indiana 47907-2054; Email: kgonzalez@purdue.edu.
2. Smithsonian Tropical Research Institute, Panamá.
3. Department of Biology, Boston University, 5 Cummington Mall, Boston, Massachusetts 02215; Email: (KMW) kwarken@bu.edu; and (BAG) bguell@bu.edu. Send reprint requests to BAG.