Grasslands make up only about 0.7% of the land area of B.C., and most of that area is grazed by livestock. Grazing affects the habitat suitability for most grassland-dependant vertebrate species, primarily due to changes in the structure of the grassland vegetation. Approximately 16% of vertebrate wildlife species and about 44% of red- and blue-listed species in British Columbia are most closely associated with grassland habitats. Since most grasslands in B.C. are grazed, populations of species that prefer ungrazed habitats may be lower than they were historically. This report summarizes literature on the habitat requirements of grassland-dependant vertebrate species and the effects of grazing on the habitat suitability for grassland wildlife communities. Four species that use different types of grassland vegetation communities were selected for detailed literature reviews of their habitat requirements. From these habitat requirements, standards can be developed to ensure that suitable habitat is maintained for these and other species that prefer structurally diverse grasslands. Grassland small mammal communities are affected by grazing. Species richness and diversity in grasslands has been found to decrease with grazing in B.C. and elsewhere in North America. Many waterfowl species are also closely associated with grasslands in B.C., and nest density, nest success, and nest predation rates are all affected by livestock grazing.
McKenzie, K.L.. 2004. The Effects of Livestock Grazing on the Habitat Suitability of Grassland-Dependant Vertebrate Species in British Columbia: A Literature Review. Ministry of Water, Land and Air Protection. Wildlife Working Report. WR113