We thank Mary Brashier, publications editor, Department of Agricultural Communications,
SDSU, for editorial assistance and R.F. Gartner, W.D. Svedarsky, C. H. Halvorson,
and K.L. Solberg for reviewing the manuscript.
This publication is the result of a cooperative effort by the U.S. Fish
and Wildlife Service, the South Dakota Cooperative Fish and Wildlife Research
Unit, and South Dakota State University.