Nrsi can wea2009_bird behaviour and mortality monitoring
- 1. Caroline Walmsley, Lisa Keable, and David Stephenson Introduction Natural Resource Solutions Inc. (NRSI) was retained by Brookfield Renewable Power Corp., formerly Superior Wind Energy Inc., in October 2001 to participate in a study of a proposed wind power facility in Sault Ste. Marie, Ontario. The work included pre, during, and post-construction stages of development. Post-construction monitoring surveys were conducted in 2006 through to the end of October 2008 and included: •bird and bat mortality surveys •breeding bird surveys •aerial waterfowl surveys •spring and fall bird migration monitoring. Results Mortality Monitoring • 236 bat carcasses and 72 bird carcasses were found • Total estimated bat and bird mortalities were 452 and 167 respectively (searcher efficiency & scavenger removal factors) • Little Brown bat was found to be the most common fatality • This differs from other studies where long distance migratory bat species were particularly vulnerable to wind turbines (MNR 2006) • Passerines are most commonly affected by wind energy facilities in North America (Kingsley and Whittam 2005) • The majority of the 22 species of bird carcasses References Kingsley, A., and Whittam B. 2005. Wind Turbines and Birds: A Background Review for Environmental Assessments. May 12, 2005. Ministry of Natural Resources. 2006. Wind Power: Bat Ecology Background Information and Literature Review of Impacts. December 2006. Natural Resource Solutions Inc. 2009. 2006, 2007 and 2008 Bird and Bat Mortality Report. Prince Wind Power Project. Prince Wind Power Project Natural Resource Solutions Inc. 2009. Fall 2004, 2005, 2006, 2007 and 2008 Bird Behaviour Monitoring Report Prince Wind Power Project. Natural Resource Solutions Inc. 2008. Fall 2006 Bird and Bat Mortality Monitoring Prince Wind Power Project. Natural Resource Solutions Inc. 2008. 2007 Bird and Bat Mortality Monitoring Prince Wind Power Project. Study Site • Located in Sault Ste. Marie, Ontario, the Prince Wind Farm is comprised of 126 turbines, resulting in a total combined capacity of 189MW • The final study area is 10,000ha in size, and spans approximately 25 kilometres Study Design & Techniques Mortality Monitoring • Commenced operation in fall of 2006, covering 4 seasons ending in October 2008 • Monitoring methods varied but was conducted at all 126 turbines in 2008 • All areas were searched within a 45m radius from the base of each turbine • Searcher efficiency and scavenger removal trials were conducted Bird Surveys • Pre-construction behaviour, migration and breeding bird surveys • Post-construction monitoring included behaviour migration, breeding surveys, and aerial waterfowl survey Other Trends Observed: • Bat mortalities peaked during periods known for summer swarming events • Bird mortalities peaked during spring and fall migration • No trends were observed with respect to mortalities at lit versus unlit turbines Searcher Efficiency and Scavenger Removal Trials • Factors in adjusting estimated mortalities • Searcher efficiency varied, but typically 50 to 60%, with searcher-dog teams generally 100% Conclusions Mortality • Average adjusted mortalities in 2006 - 2008 similar to reported totals for wind power projects on open agricultural lands in North America, and well below mortality estimates for other wind power projects in forested ridge landscapes Bird Behaviour Monitoring • No evidence suggesting that species composition and/or abundance has changed substantially between pre-turbine and post-turbine monitoring • No evidence that flight directions have altered as a result of turbine operations • No evidence to suggest that raptors are avoiding the wind farm Breeding Bird Surveys • No adverse effects relating to breeding birds within the Prince Wind Farm detected Waterfowl Survey • Waterfowl are not being negatively impacted by operating turbines • Scavenger removal rates followed a semi-log relationship, and increased from spring to fall Year Bats Birds mortalities/ turbine/yr mortalities/ MW/yr mortalities/ turbine/yr mortalities/ MW/yr 2008 3.59 2.39 1.33 0.89 2007 1.63 1.09 0.43 0.29 2006 1.67 1.11 2.15 1.43