1. Department of Agronomy and Horticulture and School of Natural Resources; University of Nebraska-Lincoln; 3310 Holdrege Street Lincoln NE 68583 USA
2. School of Natural Resources; University of Nebraska-Lincoln; 3310 Holdrege Street Lincoln NE 68583 USA
3. Department of Agronomy and Horticulture; University of Nebraska-Lincoln; 312 Keim Hall Lincoln NE 68583 USA
4. Nebraska Game and Parks Commission; Wildlife Division; 2200 N. 33rd Lincoln NE 68583 USA
5. Nebraska Game and Parks Commission; Wildlife Division-Sandhills District; P. O. Box 508 Bassett NE 68714 USA