Get reliable rangeland science

Diversity in the structure and botanical composition of grazing lands is commonly reported to provide the variety of habitat types needed for a diversity of birds. It follows that the use of a variety of grazing strategies on a management unit or across a rangeland landscape leads to vegetation heterogeneity and diverse bird communities. We selected management units in a rangeland landscape in the Nebraska Sandhills that were managed with a variety of commonly-used grazing strategies, including continuous stocking, deferred and rest rotation grazing, and short duration grazing. We hypothesized that habitat characteristics and abundance of songbird species would vary among units within this landscape. The Sandhills region is mixed prairie dominated by warm-season tallgrasses within a rich mixture of cool-season grasses, sedges, forbs, and shrubs. Visual obstruction readings (VOR), plant cover, and songbird composition and abundance data were collected in 2003/2004 and 2014/2015 on rangelands managed with a variety of grazing strategies. VOR and measures of plant/ground cover generally did not differ among grazing strategies, although these measures were affected by timing of grazing and stocking rate, and differed among pastures within a grazing strategy. Grassland birds (e.g., grasshopper sparrow and lark sparrow) responded to habitat variables, such as standing dead cover and VOR, but bird abundance and composition generally did not vary by grazing strategy. Overall, structural heterogeneity of vegetation did not consistently differ among ranches managed with different grazing strategies and was not sufficient to affect songbird abundance and composition. Vegetation composition and structure of upland range in the Sandhills is largely homogeneous because rangeland managers have been effective in managing for the dominant native tall and mid-grasses and for optimizing ground cover, regardless of the grazing strategy used. Range managers use different grazing strategies based on cattle enterprise objectives, tradition, and management style but they mostly have comparable vegetation cover goals. To provide habitats for more diverse avian communities, conservation planners should consider management tools that create depth of disturbance beyond that provided by typical grazing strategies.