According to the Breeding Bird Survey (BBS), all grassland bird species have declined significantly over the last 30 years. Many are either Red- or Blue-listed in British Columbia. We were interested in determining the habitat requirements of grassland birds so that their needs could be considered when developing land management protocols. Livestock grazing has been hypothesized to negatively affect bird populations and few data test this hypothesis, mostly because there are few control sites. We conducted spot mapping surveys of breeding birds in May 1994 and 1995 at 10 study sites that represented a gradient of known grazing history in the semiarid shrubsteppe dominated by antelope-brush in the south Okanagan. We included 3 sites that had not been used by livestock for 75 years. Density of breeding pairs, encounter rates, and the distribution of individual territories across and within the 10 sites were used as indicators of bird response to habitat characteristics...
Krannitz, Pam G., Rohner, Christoph. 1999. Habitat Relationships of Endangered Grassland Birds in the South Okanagan (in Proc. Conference Biology & Management of Species and Habitats at Risk). Ministry of Environment, Lands and Parks. Conference Biology & ManagementProceedings. Vol. 2
Topic: Species and Ecosystems at Risk
Keywords: bird diversity, Brewer’s sparrow, lark sparrow, species richness, tree invasion, vesper sparrow, western meadowlark, habitat, livestock grazing