1. Department of Ecology and Conservation Biology, Texas A&M University, College Station, TX 77843, USA
2. USDA Agricultural Research Service, Fort Keogh Livestock and Range Research Laboratory, Miles City, MT 59301, USA
3. USDA Agricultural Research Service, Aerial Application Technology Research Unit, College Station, TX 77845, USA
4. Texas A&M AgriLife Research, San Angelo, TX 76901, USA
5. Texas A&M AgriLife Research, Sonora, TX 76950, USA