Grassland songbirds in North America are experiencing significant declines. This is in part due to changes in disturbance regimes, such as grazing. Grazing at different stocking rates alters vegetation structure and composition, and can create habitat used by grassland bird communities. However current management practices emphasize moderate grazing to maximize production gains, which can reduce habitat for some bird species. It is important to manage grazing on remaining grasslands to provide habitat for a complete avian community. Our study examines the impacts of cattle stocking rates on grassland songbird communities. The study area contains nine 300 ha pastures in Grasslands National Park, Saskatchewan, in native mixed-grass prairie. There are three ungrazed pastures; the remaining pastures are grazed from approximately 0.2 to 0.8 AUM/ha. In the summer of 2011 and 2012, 100 m fixed-radius point counts were conducted at ten points within each pasture. At each survey point ten frames within a 20 m x 50 m Whittaker plot were used to assess vegetation composition and structure. Generalized estimating equations show that some species are exhibiting significant negative (e.g. Sprague's pipit) or positive responses (e.g. chestnut-collared longspur) to increased stocking rate (AUM/ha). In the fall of 2012 we will analyze the data using generalized linear mixed-effect models. Additionally, we will create continuous models showing the effect of specific habitat variables (e.g. percent shrub and grass species cover) on abundance of each avian study species. This study will provide information to help manage cattle grazing for avian species of conservation concern.
Oral presentation and poster titles, abstracts, and authors from the Society for Range Management (SRM) Annual Meetings and Tradeshows, from 2013 forward.