Temporal Effects of Grazing Regimes on Non-Game Birds in North Dakota Grasslands

Grazing occurred naturally in the northern Great Plains and influenced many natural processes in grassland ecosystems, including the habitat selection of breeding birds. Grazing, mainly for livestock production, is still an important land use practice and is one that impacts millions of hectares on both public and private land in the United States. To better understand how long-term grazing treatments affect non-game breeding birds, a study was conducted at the Central Grasslands Research Extension Center (CGREC) in south-central North Dakota during 2001 and 2002 and results were compared to two earlier studies, one in native prairie and the other in Conservation Reserve Program (CRP) grasslands. Season-long and twice-over grazing treatments were in place for 19 years on native prairie sites and 10 years on CRP sites. Bird surveys were conducted along permanent belt transects three times per year and vegetation structure was characterized from measurements taken parallel to each bird survey transect, twice per year for each treatment plot. Non-game bird densities and species richness during this study period were lower for all grazing treatments in native prairie and CRP grazing system grasslands when compared to earlier studies. Among grazing treatments, rotational grazing treatments supported more species and are probably more beneficial because they provide areas of undisturbed habitat during the breeding season. Results from this study suggest that some grazing practices on native or seeded grass land habitats can be applied for long-periods of time without negative effects on certain species of grassland non-game birds