Description

Rangeland birds in the Southern High Plains, USA evolved within a context of fire and grazing (i.e., pyric herbivory), a disturbance regime that played a dominant role in shaping rangelands in this region but has been absent since the 1880s. A management technique known as patch-burn grazing was used to mimic the heterogeneity in vegetation created by the historical disturbance regime of fire and grazing in sand sagebrush (Artemisia filifolia) rangelands. We compared nest survival of Cassin's sparrows (Peucaea cassinii), field sparrows (Spizella pusilla), and lark sparrows (Chondestes grammacus); species richness; and densities of 11 bird species between rangelands managed with patch-burn grazing and rangelands managed with traditional management (i.e., seasonal grazing) in Oklahoma from 2006 to 2008. Estimates of nest survival were similar between patch-burn and traditional pastures (Cassin's sparrows: 51% and 57%; field sparrows: 18% and 22%; and lark sparrows: 14% and 12%, patch-burn and traditional, respectively). Species richness was higher in patch-burn pastures compared to traditionally managed pastures. Densities of the majority of avian species (73%) were similar between treatments; however, lark sparrow densities were 5 times more abundant in patch-burn pastures and grasshopper sparrows (Ammodramus savannarum) and brown-headed cowbirds (Molothrus ater) were >3 times more abundant on traditional pastures. Our results suggest that introducing patch-burn grazing management to sand sagebrush rangelands is not detrimental to nesting shrubland birds, and the creation of heterogeneity through patch-burn grazing can increase avian species diversity. Furthermore, some species such as lark sparrows may benefit from patch-burn grazing. Patch-burn management may be an important tool to assist in the recovery of biodiversity in this ecosystem.