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Grassland bird species have declined dramatically since 1966. This decline can be linked to changes in land use practices, such as grazing. I examined the effects of cattle grazing on the abundance of birds by testing the predictions of the More Individuals Hypothesis (MIH). The study was conducted in Grasslands National Park of Canada (GNPC) in Saskatchewan. Point counts were used to sample richness and relative abundance of birds. I sampled two groups of invertebrates: grasshoppers and carabid beetles. In addition, vegetation measurements were taken to assess the intensity of grazing. I found that (1) grasshopper abundance, richness and diversity were higher in grazed pastures; (2) carabids showed mixed responses to grazing; (3) bird abundance was correlated with carabid abundance, thus supporting the assumptions of the MIH. Overall, my results indicate that grazing can be beneficial for both birds and their invertebrate prey in southern Saskatchewan mixed-grass prairies.

Avian point counts were conducted in tall-grass prairie fragments and adjacent grassland and agricultural matrix habitat in southern Manitoba. Bird density/abundance was compared between habitat types, while variables within prairie at local, patch or landscape level were modeled to determin avian habitat selection. Prairies and matrix grassland habitat supported the same number of species in both years, and densities of all focal bird species were the same in non-native grasslands as compared with native tall-grass prairies. Overall species richness in tall-grass prairies was mainly driven by vegetation variables. Variable responses to habitat structure and composition between avian species indicate that managing grasslands to promote heterogeneity is important to sustain a diverse assemblage of avian species. As individual species were affected most strongly by vegetation structure and richness, it follows that management of prairie vegetation through techniques such as grazing and prescribed burning could optimize habitat usability for birds.

This new resource on the management and conservation of grassland/prairie birds has been posted at the Northern Prairie Wildlife Research Center site. This report "contains findings from the first year of a study to test the idea that Bird Conservation Areas can maintain populations of breeding grassland birds." It is available for download in .zip format.

The Northern Prairie Wildlife Research Center (NPWRC) has posted several new resources online. This resource, by Maiken Winter and colleagues, was published earlier this year in Condor [102(2):256-266]. It may be browsed online or downloaded in .zip format.

The Northern Prairie Wildlife Research Center (NPWRC) has posted several new resources online. This resource, by Maiken Winter and colleagues, was published earlier this year in Condor [102(2):256-266]. It may be browsed online or downloaded in .zip format.