Linear disturbances in grassland systems, including powerlines, roads, and pipelines, have led to fragmented landscapes, soil degradation, and declines in sensitive species. Grassland birds, in particular, have undergone steep declines in populations due to the loss and degradation of grassland habitat. The construction of a major new transmission line in Southeastern Alberta in 2014 provides a unique opportunity to determine the direct effects of powerline construction on songbird species by comparing baseline pre-construction data from 2012 and 2013 to data from 2016 following transmission line development. 10-minute point counts were conducted across a 300m grid at Mattheis Ranch, located in Southeastern Alberta, during the breeding season of the summers of 2012, 2013, and 2016. 372 point count sites were sampled in 2012 and 2013, and a subset of these point counts were sampled in 2016 to focus on specific disturbances on the landscape and control areas without recent disturbances. Transects were blocked by treatment (road only, powerline only, road with powerlines on one side, road with powerlines on either side, and control). Other covariates, such as weather conditions during point counts, vegetation cover, grazing, range health scores, and ratings of visual obstruction were also collected. Species richness did not differ between treatments, but did increase with greater distance to linear disturbances. However, species-specific responses were more variable. Grasshopper sparrows demonstrated the greatest response to roads and powerlines, while other species, such as the Upland sandpiper and Clay-colored sparrow, either increased near roads and powerlines or were not affected. Further analyses will look at how community structure changes with disturbance and comparisons will be made between years to evaluate the direct effect of powerline development in grassland habitats on songbirds, and what might be done to mitigate the effects of future transmission line developments on grassland songbirds.
Oral presentation and poster titles, abstracts, and authors from the Society for Range Management (SRM) Annual Meetings and Tradeshows, from 2013 forward.