Potential impacts of large wind energy developments to migratory and resident bird populations in the Prairie Pothole Region within North Dakota and South Dakota remain poorly understudied even though 2,230 turbines are actively generating power in these states and numerous wind energy projects have been proposed. No information on potential direct mortality from wind turbines is available for the Missouri Coteau portion of the region across multiple avian guilds. The objectives of a new USGS study are: 1) to evaluate the influence of landscape composition on potential wind turbine-related direct mortality to migratory and resident birds in the south-central Missouri Coteau during spring migration and nesting periods; 2) to evaluate the influence of nesting density on wind turbine-related direct mortality of raptors; 3) to identify those species most at-risk in the Missouri Coteau to mortality from wind-turbine strikes; and, 4) to calculate fatality rates for species of concern.
The USGS has completed a 10-year field investigation of the influence of wind facilities on breeding grassland birds. The study demonstrated that wind facilities placed in mixed-grass prairies influence the distribution of grassland birds for years after construction. The study included a before-after-control-impact design that incorporated multiple years, nine species, and replicated impact and reference sites within 3 facilities. This approach makes the study one of the most rigorous to use an optimal impact assessment design to evaluate wind facilities. This long-term study distinguished between immediate, short-term effects and delayed, or sustained effects. The study also determined distances at which individual bird species displayed avoidance or attraction.
Related Publication: Effects of wind-energy facilities on grassland bird distributions
The USGS found that most wind towers in the Great Plains have been constructed in places with habitat characteristics not preferred by sandhill cranes. The findings suggest that the current distribution of wind towers may be of relative low risk to sandhill cranes wintering in this region.
Numerous wind-energy projects have been constructed in the central and southern Great Plains, the main migration corridor and wintering area for midcontinent sandhill cranes. Crane populations are potentially vulnerable to wind energy infrastructure, specifically increased mortality due to collisions and displacement from roosting or feeding sites. The USGS has assessed potential risk of wind towers using location data from cranes marked with platform transmitting terminals with and without global positioning system capabilities. The distributions of sandhill cranes pre-construction of wind towers were compared to distributions with current tower locations. This assessment provides: 1) an estimate of potential risk to the midcontinent population of sandhill cranes at their main migration and winter grounds; 2) information for local-scale decisions about relative risk of existing towers; 3) guidance for locating future developments; and 4) information that can be combined with assessments from other species to develop multi-species risk models.
Top Photo: Baird's Sparrow. Photo courtesy of Rick Bohn, U.S. Fish and Wildlife Service.