E-mail Alert
500,000 sage-grouse data points, 5 years of study
provide important conservation, planning insights for PCW
Company selected to present to Wyoming Sage-Grouse
Implementation Team

CHEYENNE, Wyo., Jan. 28, 2015 — Power Company of Wyoming LLC's nearly five years of high-tech sage-grouse tracking has yielded more than 500,000 precise data points and revealed important site-specific insights into where, when and how greater sage-grouse live on and around the Overland Trail Ranch in Carbon County, Wyoming.

PCW and its environmental scientists were invited to present these insights today at the Wyoming Governor's Sage-Grouse Implementation Team meeting in Cheyenne. PCW has the most robust pre-construction dataset ever collected specific to sage-grouse and energy development. The company is planning the Chokecherry and Sierra Madre Wind Energy Project south of Interstate 80 near Rawlins and Sinclair.

"We are developing this wind power project consistent with wildlife conservation. The constant flow of data delivered by GPS tag technology accurately reveals facts about our sage-grouse behaviors and habitat use that previous technology just couldn't capture," said Garry Miller, PCW vice president of land and environmental affairs. "Multiple years and millions of dollars of scientific monitoring and analysis helps us see trends and implement our conservation measures and project design in the most beneficial way."

Launched in April 2010, PCW's privately funded sage-grouse monitoring program is watching and learning from about 50 female sage-grouse tagged every year with GPS devices. The lightweight GPS tags transmit location data via satellite every 1 to 6 hours, depending on the season. Scientists from SWCA Environmental Consultants working for PCW analyze the location data in conjunction with vegetation, topography, weather and other types of scientific data to understand what a "day in the life" of a sage-grouse is like.

This monitoring program, along with extensive vegetation mapping and analysis, has assured that:

  • PCW has sited its wind turbines and related infrastructure in a way that avoids and minimizes potential impacts to sage-grouse to the greatest extent practicable.
  • PCW is implementing conservation measures in places that will deliver the greatest benefit to birds.
  • The program will expand the body of scientific knowledge about sage-grouse and its potential response to wind energy development. The pre-construction data provides a habitat use and behavior baseline to which post-construction data will be compared.

The study area covers about 750,000 acres (over 1,170 square miles) of south-central Wyoming, including on and well beyond the Overland Trail Ranch where the CCSM Project will be built. Already, PCW has worked with The Overland Trail Cattle Company LLC to implement sage-grouse conservation measures across the ranch such as marking, removing and replacing high-risk fences; deploying "bird ladders" in stock tanks to minimize drowning risk; prohibiting hunting access; and working to improve and wisely manage the mosaic of vegetation that sage-grouse need to survive. In addition, all wind turbines are sited outside of Wyoming's designated sage-grouse core areas.

PCW also is collaborating on a male sage-grouse study with experts from SWCA Environmental Consultants, the University of Missouri, USFS Rocky Mountain Research Station, and Wyoming Game and Fish Department. Funded in part by the National Wind Coordinating Collaborative, this study uses a Before-After Control-Impact design to investigate and quantify the potential impacts of constructing and operating a wind energy project. This long-term study includes five years of pre-construction study, monitoring during construction, and five years of post-construction research.

Among the site-specific results and observations gathered from the past five years in the study area and shared with the Sage-Grouse Implementation Team:

  • PCW's team counts 58 leks three times each season in the study area. Collectively, attendance is relatively low in leks located in the Chokecherry and Sierra Madre treatment areas, but over the years attendance has slightly increased, potentially due in part to PCW's conservation measures.
  • Across the study area, less than 25% of the available landscape is collectively used by sage-grouse throughout the year. Their space use ranges from less than 2% to 10% of the landscape at any one time.
  • Hen that live in designated core areas spend the vast majority of their time — over 80% — in core areas, indicating that core areas are protecting the birds they are designed to protect.
  • Sage-grouse change where they live and how far they roam by the season. In general, sage-grouse range the least in the summer months, because they are tied to the wetter, greener areas that are more limited on the landscape. They range the most in the winter months to seek food and cover.
  • The birds are loyal to the transition corridors they use between seasonal habitats, and infrastructure types are not a barrier to their movements. GPS tracking reveals they cross the North Platte River, Interstate 80, the Union Pacific rail lines, and electricity transmission and distribution lines to get where they want to go.
  • Male sage-grouse stay close to their chosen leks, with 80% of their use during the lekking season occurring within 0.6 miles of the lek. Female sage-grouse range a little further to establish their nests, with 82% of their nests established within 2 miles of a lek.
  • Sage-grouse benefit from a diversity of landscapes and vegetation to meet their lifecycle needs. For example, PCW has observed that irrigated hay meadows provide important summer and brood habitat for many female sage-grouse. However, relic agricultural fields that have insufficient cover are not used by sage-grouse, indicating that restoring this type of land to native vegetation or active agriculture could provide a conservation benefit to sage-grouse.
  • Male sage-grouse are sensitive to Wyoming's winds, and many days of over-10 mph winds will keep them away from the lek for over a week.
  • Over half of hens' initial nesting attempts fail within the first 7 days, and 23% fail within the first 3 days, typically because of weather, abandonment or predators. Successful hens are more likely to return to the same nesting area used the previous year, while failed nesters move farther distances in search of a different nesting area the following year.

PCW is continuing its monitoring program and its collaboration on scientific papers and publications. The data already has resulted in two master's degree theses by University of Missouri students and multiple presentations delivered by SWCA at the 2012 and the 2014 Sage & Columbian Sharp-tailed Grouse Workshop, hosted by the Western Association of Fish and Wildlife Agencies and considered the pre-eminent scientific venue for research specific to these birds. In addition, in 2010 PCW submitted to the U.S. Fish and Wildlife Service and other agencies a draft Candidate Conservation Agreement with Assurances, which PCW intends to update with its five years of scientific data and resubmit this year.

For more information about the Chokecherry and Sierra Madre Wind Energy Project, visit www.powercompanyofwyoming.com.

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