difference in abundance between grazed plots. + / NC Grazing Western UT Low-shrub Density (pairs/40 Four 9-ha plots Heavy grazing in early Medin 1986 desert ha) censused using winter increased Williams spot-map Horned Lark density, method. but no significant difference between ungrazed and middle and late winter grazing. + Grazing Southeastern AZ Semidesert Bird counts Daily sampling of Horned Lark numbers Bock et al. 1984 grassland census plots by 6-8 significantly increased observers. on grazed plots during the summer, but winter sampling inconclusive. + Grazing Northern Great Shrub steppe Density index One bird census per Increasing density as Kantrud and Plains (pairs/min x 103) 65 plot hollow grazing intensity Kologiski 1983 square technique increases. Pattern holds across all subregions, including shrub steppe. NC Grazing Eastern ID Big sagebrush Successful nests Visual observation in No difference in Reynolds and (sheep) and former 4-ha grid. grazed vs ungrazed Trost 1980 sagebrush range plots. reseeded with crested wheatgrass Grazing - Great Basin Various habitat Bird abundance One-mile strip census Major decrease in low Page et al. 1978 (CA/NV) types including sagebrush; low sagebrush inconclusive in big and big sagebrush habitats. sagebrush Prefer low grass, not bare ground? + Grazing Northern CO Shortgrass N/A Literature Review Grazing in shortgrass Ryder 1980 (Central Plains prairie prairie, not sagebrush. Experimental Horned Lark preferred Range) bare ground
difference in abundance between grazed plots. Grazing + / NC Western UT Low-shrub desert Density (pairs/40 ha) Four 9-ha plots censused using Williams spot-map method. Heavy grazing in early winter increased Horned Lark density, but no significant difference between ungrazed and middle and late winter grazing. Medin 1986 Grazing + Southeastern AZ Semidesert grassland Bird counts Daily sampling of census plots by 6-8 observers. Horned Lark numbers significantly increased on grazed plots during the summer, but winter sampling inconclusive. Bock et al. 1984 Grazing + Northern Great Plains Shrub steppe Density index (pairs/min x 103) One bird census per 65 plot hollow square technique Increasing density as grazing intensity increases. Pattern holds across all subregions, including shrub steppe. Kantrud and Kologiski 1983 Grazing (sheep) NC Eastern ID Big sagebrush and former sagebrush range reseeded with crested wheatgrass Successful nests Visual observation in 4-ha grid. No difference in grazed vs ungrazed plots. Reynolds and Trost 1980 Grazing - Great Basin (CA/NV) Various habitat types including low sagebrush and big sagebrush Bird abundance One-mile strip census Major decrease in low sagebrush; inconclusive in big sagebrush habitats. Prefer low grass, not bare ground? Page et al. 1978 Grazing + Northern CO (Central Plains Experimental Range) Shortgrass prairie N/A Literature Review Grazing in shortgrass prairie, not sagebrush. Horned Lark preferred bare ground Ryder 1980