BEEF-CATTLE DISTRIBUTION PATTERNS ON FOOTHILL RANGE

A 3-year experiment designed to quantify the spatial and temporal utilization patterns of range sites by beef cattle on summer foothill range was conducted on the Wick Brothers Management Unit of the Wyoming Game and Fish Commission, 8 km w. of Arlington, Wyo. The grazing seasons, in replicate pastures, were from 15 July-9 August, 15 June-26 July, and 15 June-2 August in 1980, 1981, and 1982, respectively. Daily observations were made of radio-telemetry collared cattle (3 per pasture). Cattle dispersion was constrained by the spatial distribution of water and slope. Across 3 seasons, 77% of observed use was within 366 m of water. Approximately 65% of the land area was beyond 723 m from water and sustained only 12% of observed use. Cattle concentrated use (79%) on slopes less than 7%. Consequently 35% of the area, on or surrounded by slopes > 10%, received only 7% of observed use. Loamy, grazable woodland and wetland/subirrigated range sites were most preferred and accounted for over 65% of observed use while occupying less than 35% of the land area. Overall, coarse upland, very shallow and shallow loamy sites were not preferred; however, site preference varied as areas further from water were utilized. Observed use was significantly (P < 0.10) correlated (r 0.41 to 0.69) with standing crop and crude protein standing crop over various growth form characteristics of the forage component. Associated stepwise regression models accounted for 44 to 73% of the variation in observed use over the 1982 grazing season. As the forage complex became more similar, in terms of standing crop and crude protein content, significantly less (P < 0.05) variation in use was accounted for by the forage variables (0-37%).