Abstract
Red Pine Wind Farm, LLC is currently operating the 200-megawatt (MW) Red Pine Wind Project (Project) in Lincoln County, Minnesota. The Project became operational on January 31, 2018 and consists of 100 utility scale Vestas, 2.0 MW V110 (50 turbines) and V100 (50 turbines) wind turbine generators. Each turbine is a 3-bladed, upwind, horizontal axis wind turbine with rotor diameters of 100 meters (m; 328 feet [ft]; V100) and 110 m (361 ft; V110), tubular steel tower, and 80 meters (262 feet) hub height. Red Pine Wind Farm, LLC contracted Western EcoSystems Technology, Inc. (WEST) to complete a post-construction wildlife fatality monitoring study consistent with the goals and objectives of Tier 4 of the US Fish and Wildlife Service Land-Based Wind Energy Guidelines and the Minnesota Department Natural Resources’ Avian and Bat Survey Protocols. This report presents the results of a post-construction fatality monitoring study conducted for the Project from March 2018 to November 2018.
The post-construction bird and bat mortality monitoring studies began on March 18, 2018, and continued through November 15, 2018. The objectives of the monitoring studies were to provide a summary of documented bird and bat fatalities, present estimates of searcher efficiency and carcass persistence, and calculate annual fatality rates at per turbine and per MW levels.
Carcass searches were completed by WEST technicians, trained in proper search techniques, between March 18, 2018 and November 15, 2018. A total of 10 turbines had a search area of 120 m x 120 m (394 ft x 394 ft) cleared of vegetation and centered on the turbine; these cleared plots were searched at a frequency of four times per week. The gravel roads and pads at the remaining 40 turbines were searched within 60 m (197 ft) of the turbine; these road and pad searches occurred once a week during the study period. Searcher efficiency and carcass persistence trials were conducted throughout the study period using bat, small bird, large bird, and raptor carcasses.
During the study, 79 birds comprising 39 identifiable species were found during scheduled searches. Seven casualties were unidentified small birds or passerines. Three raptors were found during the study: one red-tailed hawk, one sharp-shinned hawk, and one Swainson’s hawk. The ruby-crowned kinglet and marsh wren were found most frequently, with nine and eight records, respectively, representing approximately 11.4% and 10.1%, respectively, of the overall composition. The red-eyed vireo and sedge wren each had four records (each approximately 5.1% of the overall composition), and the golden-crowned kinglet was found three times (3.8% of the overall composition). The remaining species were all documented once or twice. No federally listed or state-threatened, endangered, or species of special concern birds were documented during surveys. Eight avian species (19 individuals) listed as Species of Greatest Conservation Need in Minnesota’s Wildlife Action Plan 2015 – 2025 were documented: Le Conte's sparrow (two found), marsh wren (eight found), ovenbird (one found), Philadelphia vireo (one found), sedge wren; (four found), Swainson's hawk (one found), swamp sparrow (one found), and Virginia rail (one found).
A total of 168 bat carcasses were found at the Project between May 5 and October 18, 2018; 115 were found on cleared plots, 50 bats were found on road and pads, six of these were found incidentally on search plots but not during a search. Four species of bats were found: hoary bat (63 found, 37.5%), eastern red bat (44 found; 26.2%), silver-haired bat (37 found, 22.0%), and big brown bat (24 found, 14.3%). One special status bat species was documented: the big brown bat is a state species of special concern in Minnesota; no federally or state-listed threatened or endangered bat species were documented during the surveys. Hoary bats and eastern red bats are listed as Species of Greatest Conservation Need in Minnesota’s Wildlife Action Plan 2015 – 2025.