Although wind energy is widely accepted as renewable, green energy, wind farms can adversely affect birds. In 2013, Environment Canada estimated that on average 8.2 birds were killed per year per wind turbine from collisions at the 43 wind farms sampled. As well 1.23 hectares of bird habitat was lost per turbine as a result of vegetation clearing.
In 2014, according to CANWEA, Canada had approximately 5,500 wind turbines. Adjusting estimates from Environment Canada, this translates to roughly 45,000 bird deaths from collisions with the turbine blades and an annual loss habitat for over 10,000 breeding pairs of birds. The wind- energy industry is expected to increase ten-fold in 10 to 15 years resulting in approximately 450,000 birds killed per year and displacement of 100,000 pairs of birds if current practices and patterns persist.
Wind farms contribute far less to bird mortality than predation by domestic and feral cats, and collisions with buildings, communications towers and power lines. However, certain bird species—several of which are at-risk or declining species—are affected more than others by certain projects. Some wind energy projects located in high risk areas (with lots of bird traffic or nearby colonies) have proven to have population-level impacts on species of eagle, vulture and tern in Europe and Golden Eagles in California.
Nature Canada encourages the wind energy industry to adopt bird-friendly siting of wind turbines and operating practices including avoidance of officially recognized Important Bird and Biodiversity Areas which cover less than 3 percent of the land and water surface of Canada. Nature Canada has intervened in a law suit to stop a badly sited wind energy project to be built in a rare limestone plain and wetland habitat along the shore of eastern Lake Ontario, a major migratory corridor, and has made several submissions to Ontario regulators about impacts of proposed wind energy projects on birds and species t risk. We work with other groups, including the American Bird Conservancy to advocate for avoidance of industrial wind energy projects (or any industrial projects) within IBAs in Canada. Nature Canada, Canadian Wind Energy Association, and Pembina have also sponsored a workshop on wind energy projects and Important Bird and Biodiversity Areas.
The Environment Canada study identified the ten bird species most frequently reported as casualties of wind energy projects
|Species||No. of Carcasses||Total Predicted Mortality (Annual)|
Bird Studies Canada hosts a database on behalf of the Canadian Wind Energy Association (CANWEA), the Canadian Wildlife Service (CWS) and the Ontario Ministry of Natural Resources (OMNR) in which companies voluntarily report the results of monitoring studies. Unfortunately, most companies either do not monitor for deaths of birds and bats from collisions, or do only monitor for required periods upon becoming operational (e.g. 2 to 3 years). While data are not linked to specific projects, the database does provide ranked lists of species, and enquiries of the data holders on specific species can be made.
The Wind Energy Bird and Bat database produced a report, updating and discussing data in 2014, that presented revised lists of casualties, including a thorough discussion on sources of bias, including radius bias, which is generally not accounted for in post operation monitoring studies reported in Canada. Radius bias occurs when estimates are based on the number of birds within a fixed distance radius of the turbine base – usually 50 m. in Canada. Research suggests that half or more of the birds fall beyond the 50 metres. Open discussion of this bias is a very positive sign that the industry is moving towards increased transparency, and more than many other sectors. The following table, extracted from the report shows the top 20 species collected at wind energy projects in Canada, based on fractional ranking and percent species composition.
Swallows hit hard
Four of the seven regularly-occurring swallow species in Canada, all in serious declines in parts of their ranges, appear on this list, including three swallow species in the top ten ranking. Species number 4, the Purple Martin, is declining at 5 to 7 percent annually in Eastern Canada. The high number of swallow species is red flag that merits conservation attention, particularly with the anticipated industry build-out. The vulnerability of swallow species is likely a result to the foraging habits (catching insects on the wing), putting them in the airspace of the turbine blades), and the location of projects in areas where swallows congregate or roost (Great Lakes coastline marshes in southern Ontario).
Case Study: Wolfe Island Ontario
Wolfe Island Wind Energy Project has been operating since 2009. Wolfe Island, located in in eastern Lake Ontario at the mouth of the St. Lawrence River, would appear from a wind energy developer as an ideal location for a wind energy project as it receives largely unimpeded winds that sweep over the expanse of Lake Ontario. The island is also an Important Bird and Biodiversity Area for several reasons, and supports globally significant numbers of waterfowl on its offshore shoals and species at risk on its grassland and other habitats.
The project was opposed during its application phase by a range of organizations including Nature Canada, but it was permitted and went forward. TransAlta, the project owner, published data from monitoring studies on collision mortality of birds and bats, effects on breeding birds and effects on waterfowl behaviour for the first three years of operation, a requirement of its approval permit. Though their data were not corrected for radius bias (did not include an adjustment for birds that landed outside the 50 metre radius sampling zone) nor crippling bias, they did provide a good picture the impact of this project through consistent monitoring and biannual reporting.
In the first year of monitoring the project recorded the highest rates of bat and bird casualties of any project in Eastern North America for projects with more than a few wind turbines (86 on Wolfe Island). Of particular concern were the high numbers of species of conservation concern that were being killed. Though not yet on COSEWIC’s list of Canada’s threatened species, Purple Martin is a likely candidate in the next few years. There were high numbers of this species being killed, perhaps as many as 100 annually. For a species declining at nearly 7% per year in Ontario, this is a significant additional stress to an already stressed population. Islands in Eastern Lake Ontario are important breeding and staging sites for Purple Martin and other swallow species like Tree Swallow, all of which are in steep decline. A large regional post-breeding roost for Martins and other swallows is located on Wolfe Island. It seems possible that birds using this roost are exposed to the added risk of the wind energy plant, and often fall victim to the turbine blades.
Bobolink was another species that is hit hard at Wolfe Island. Bobolink is a threatened species in Ontario and so recognized by COSEWIC. The extensive pasture, hayfields and alvar habitat of Wolfe Island provide important breeding habitat for this species. Building wind turbines in its prime breeding habitat impacts the population both by reducing available habitat (1.3 ha per turbine) and through direct mortality as well as an avoidance impact.
Red-tailed Hawk was another species that is severely impacted. Some birds of prey appear to be extremely vulnerable, as evidenced in the information from the Altamont site in California.
To their credit, Trans Alta has modified the operations of their turbines to reduce impact on migrating bats.
Nature Canada has adopted the Bird Smart program developed by American Bird Conservancy which calls for mandatory standards on the wind energy industry to protect birds. Bird Smart calls for careful siting of wind projects, operation and construction mitigation, bird monitoring, and compensation, to reduce and redress any unavoidable bird mortality and habitat loss:
Siting: Bird-smart wind projects should be located in places where the risk to birds is minimalized including altered habitats such as farmland and industrial land. Examples of areas to avoid may include migratory bottlenecks, wetlands, raptor concentration and key nesting areas, the edges of ridges used by migrants, key habitat or flight paths for endangered or declining species, breeding concentrations of species that avoid tall structures (such as some grouse species), and in or adjacent to Important Bird and Biodiversity Areas.
Operation and Construction Mitigation: Bird-smart wind power uses the best technology and management practices to avoid and minimize harm to birds, such as by burying transmission lines in high risk areas, using lighting that minimizes nighttime migratory bird collision mortality (such as strobe lights), using un-guyed rather than guyed meteorological towers, and restoring habitat disturbed by construction.
Monitoring: Bird-smart wind power employs effective, site-specific assessments to assist with improved siting and operation, and to properly quantify impacts. Pre-construction assessments must provide sufficient data to assist with micro-siting (e.g., by the use of radar to detect local migration patterns), create an annual baseline against which post-construction studies can be evaluated, use all existing available bird study data, and be conducted during months when bird use can be expected to be at its peak at the selected site. Post-construction studies must employ mathematical models that best account for variations in local conditions and the relative difficulty of locating bird carcasses in different habitats, as well as any scavenging by predators, searcher bias, radius bias and crippling bias. Post construction monitoring is typically carried out by a consulting firm paid by the project owner. We believe that projects should be subject to third party monitoring audits from time to time.
Compensation: Bird-smart wind power redresses the loss of any birds or habitat unavoidably harmed by construction and operation to a net benefit standard. Such compensation could include acquiring additional land to protect for nature or other off-site habitat conservation projects.
You can help Nature Canada Save Bird Lives by promoting Bird Smart wind energy projects, supporting Nature Canada with a donation, and alerting us to projects proposed in Important Bird and biodiversity Areas near you.
American Bird Conservancy
Wind Energy Bird and Bat Monitoring Database