The objective of this study was to find out how grazing pressure in June or July, precipitation, and the frequency of occurrence of selected plant species effect nesting cover of sharp-tailed grouse (Tympanuchus phasianellus), based on visual obstruction (VO). Regardless of stocking rate, 90% of the VO values for June-grazed pastures met or exceeded the sharp-tailed grouse minimum cover standard (6.9 cm). This minimum cover standard was met only with light stocking rates during July-grazing. Precipitation in May was responsible for 32% of the cover variation in the ungrazed control pastures and 11% of the variation in the July-grazed pastures. Precipitation did not effect June-grazed autumn cover. The average height of autumn cover decreased from 11.0 to 7.0 cm for June-grazing, as grazing pressure increased from 16 to 90 AUD/Mg. Results show a decline in plant growth and a greater dependence of autumn cover on the herbage that remains after a grazing event. Despite the date of grazing, with a decrease in the average cover height, the quality of cover near nesting sites also decreased. Up to 12 cm in VO, the main factor for nest site selection depends on low-cover patches and/or mean visual obstruction.
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