This content is only available as a PDF.

Author notes

Manuel C. Molles Jr. (molles@sevilleta.unm.edu) is a professor, Clifford S. Crawford (ccbosque@unm.edu) is a professor emeritus, Lisa M. Ellis (lellis@sevilleta.unm.edu) is a graduate student, and Clifford N. Dahm (cdahm@sevilleta.unm.edu) is a professor in the Department of Biology, University of New Mexico, Albuquerque, NM 87131. H. Maurice Valett (mvalett@vt.edu) is an assistant professor in the Department of Biology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061.