Where the antelope play

A common saying in Wyoming is the population of pronghorn in the state outnumber that of people. 

While that's not entirely accurate-there are 400,000 pronghorn in Wyoming compared to 550,000 residents-the Cowboy State is home to more speedgoats than any other western state. Due to the large number of pronghorn in the state, the Wyoming Game and Fish Department has not conducted any in depth studies on the animal until now.

At the August 17 meeting of the Board of Carbon County Commissioners (BOCCC) the board was provided with an update from two wildlife biologists regarding a study as to if wind energy development affects pronghorn populations. The answer, according to Saratoga Wildlife Biologist Teal Cufaude and Laramie Wildlife Biologist Lee Knox, is that pronghorn are impacted by wind energy development. What is unknown, however, is how much they are impacted.

"We're here today to discuss the ongoing Shirley Basin Pronghorn Habitat Use Study. This is an ongoing project, it's a six year project so we were just going to discuss some of the details of that project and then stand for any questions you all have for that particular study," said Cufaude. "The main intent or objective of this project is to look at or evaluate (the) influence of wind energy development on movement and habitat use by pronghorn within the Shirley Basin. In particular, the study area encompassed a couple ongoing wind development projects you're probably familiar with; Ekola Flats, TB Flats and, potentially, Two Rivers."

Invenergy and handed over to Pacificorp's subsidiary, Rocky Mountain Power. The Two Rivers Wind Project is a potential development from BluEarth Renewables, but little progress has been seen since the BOCCC rejected their application in January 2020. In addition to encompassing those three project areas, the study also incorporates the Medicine Bow Pronghorn Herd Unit.

Cufaude explained to the county commissioners the reason the length of the study was six years was to capture as much data as possible through the use of GPS collars. Those collars were initially placed on 80 pronghorn in March 2018. The past two winters, however, have been hard on pronghorn populations.

"We're trying to collar enough animals that they would live throughout the project. We could not have predicted two hard winters where we saw (a) pretty high mortality with them," said Knox. "We've actually had to replace quite a few, but that was the initial 80 animals. Total number of collared animals is closer to 140."

While this study is still ongoing, with collars expected to drop off the animals in 2024 and a final report in 2025, another study has been released in the meantime. This study, conducted in 2010 and 2011, examined pronghorn seasonal habitat use in regards to the Dunlap Wind Farm. That study, which was paid for by PacifiCorp, concluded the animals did not like to be around wind turbines during the winter.

"(The) Biggest thing I think was a finding from that particular paper that was put out is it is hard to detect how pronghorn are affected by wind energy development. They don't have the fidelity or the rigid movements or seasonal use like mule deer and other species do," Cufaude said. "Although those effects might be happening, it's awfully difficult to detect."

Knox added mule deer are easier to study as they have dedicated migration routes and make clear to follow lines when mapped out. Pronghorn, on the other hand, are far more nomadic. He added data from the Dunlap Study initially showed pronghorn did not experience any negative effects from wind energy but, as the data was re-analyzed, it showed pronghorns avoided the Dunlap Wind Farm.

"Kind of the takeaways right now is that any loss of habitat is going to have negative effects on pronghorn. There will be some sort of avoidance, we just don't know that magnitude yet," Knox said. "That's why, hopefully, when we reach that six year study we'll be able to speak more clearly on that. It's very easy to say there is an effect, we just don't know what that means."

Following the update from WGFD, the questions from the commissioners appeared to try to compare and contrast wind energy development to other energy developments in the state. 

Commissioner John Espy asked how the early findings compared to a study conducted regarding oil and gas development in Sublette County and its effect on mule deer populations. Cufaude stated the findings were still early but that even the released study could not make a direct comparison between wind energy development and oil and gas development.

Commissioner Byron Barkhurst asked Knox and Cufaude about the comparison of wind energy to solar energy. While Carbon County has not seen any solar energy development as of yet, neighboring Sweetwater County has. Knox told Barkhurst comparing the two was "apples to oranges".

Finally, Chairman John Johnson asked if any information from the study was showing generational avoidance. Knox told Johnson the WGFD was trying to figure out how to collar fawns as well as does to provide that information, but it was unclear if avoidance of wind farms was passed down through generations of pronghorn.

With a number of wind energy projects still in development, and more on the horizon, the BOCCC explained to both WGFD wildlife biologists it was being considered to place a moratorium on future projects. The commissioners requested the wildlife biologists provide information to them as it became available.

The next meeting of the Board of Carbon County Commissioners will be on September 7 at the Carbon County Courthouse in Rawlins.