Bird mortality associated with wind turbines at the Buffalo Ridge wind resource area, Minnesota

Recent technological advances hale made and power a viable source of altern ative energy production and the number of windplant facilities has increase d in the United States. Construction was completed on a 73 turbine, 25 mega watt windplant on Buffalo Ridge near Lake Benton, Minnesota in Spring 1994. The number of birds killed at existing windplants in California caused con cern about the potential impacts of the Buffalo Ridge facility on the arian community. From April 1994 through Dec. 1995 we searched the Buffalo Ridge windplant site for dead birds. Additionally, we evaluated search efficienc y, predator scavenging rates and rate of carcass decomposition. During 20 m o of monitoring we found 12 dead birds. Collisions with wind turbines were suspected for 8 of the 12 birds. During observer efficiency trials searcher s found 78.8% of carcasses. Scavengers removed 39.5% of carcasses during sc avenging trials. All carcasses remained recognizable during 7 d decompositi on trials. After correction for biases we estimated that approximately 36 /- 12 birds (<1 dead bird per turbine) were killed at the Buffalo Ridge win dplant in 1 y. Although windplants do not appear to be more detrimental to birds than other man-made structures, proper facility siting is an importan t first consideration in ol der to avoid unnecessary fatalities.