CODY, Wyo.– The rush to build wind farms to fight climate change is running up against the preservation of one of the most spectacular predators in the American West – the golden eagle – as the species is on the verge of decline.
Ground zero for the conflict is Wyoming, a stronghold for golden eagles that soar on seven-foot (two-meter) wings and a prime location for wind farms. As wind turbines proliferate, scientists say deaths from collisions could drive down golden eagle numbers, which are considered stable at best and likely to plummet in some areas.
Yet climate change looms as a potentially bigger threat: Rising temperatures are expected to shrink golden eagle breeding grounds by more than 40% later this century, according to an analysis by the National Audubon Society.
This leaves golden eagles doubly vulnerable – to climate change and to wind power being promoted as a solution to this global warming.
“We have some of the best golden eagle populations in Wyoming, but that doesn’t mean the population isn’t at risk,” said Bryan Bedrosian, director of conservation at the Teton Raptor Center in Wilson, Wyo. in the United States, this risk increases.
Turbine blades hundreds of meters long are among the myriad threats to golden eagles, which are routinely shot, poisoned with lead, struck by vehicles and electrocuted on power lines.
The precarious position of golden eagles contrasts with the conservation success of their avian cousins, bald eagles, whose numbers have quadrupled since 2009. There are approximately 350,000 bald eagles in the United States, compared to approximately 40,000 golden eagles, which need much larger areas to survive and are more prone to trouble with humans.
Federal authorities have tried to limit wind turbine deaths, while avoiding any slowdown in wind power growth – a key part of President Joe Biden’s climate agenda.
In April, a Florida-based power company pleaded guilty to criminal charges after wind turbines killed more than 100 golden eagles in eight states. It was the third conviction of a major wind company for killing eagles in a decade.
Hanging from a rope 30 feet (9 meters) above the ground with a canvas bag slung around his neck, Bedrosian made his way into a golden eagle’s nest lodged in a cliff ledge. The scientist awkwardly grabbed the young eagle from the nest, slipped a leather hood over its head and then slipped it into the bag.
The six-week-old bird was lowered and carefully extracted by Bedrosian colleague Charles Preston, a zip tie around its feet as a precaution against the inch-long talons.
“The key is not to forget later to cut the zipper,” Bedrosian said.
The eaglet went on a scale – about seven pounds (3.2 kilograms). Bedrosian took blood from a wing to test for lead exposure, and Preston attached a metal identification band to each leg.
Golden eagles don’t mate until they are about 5 years old and produce about one chick every two years, so adult eagle deaths have outsized impacts on the population, Bedrosian said.
Unlawful shootings are the leading cause of death, killing about 700 golden eagles each year, according to federal estimates. More than 600 people die each year in collisions, including with cars and wind turbines.
“Wind-induced mortality was not a thing for golden eagles 10 years ago,” Bedrosian said. “I don’t want to choose the wind as the only thing. … But it’s the additive nature of all these things and many are increasing. Vehicle strikes are on the rise. Climate change is intensifying. The wind increases.
$8 million in fines and restitution
The recent criminal prosecution of a subsidiary of NextEra Energy provided insight into the extent of the problem.
The company was ordered to pay more than $8 million in fines and restitution for killing eagles at wind farms in eight states.
NextEra remained defiant after the plea deal: its chairman said bird collisions with turbines were unavoidable accidents that should not be criminalized.
Duke Energy and PacifiCorp previously pleaded guilty to similar charges in Wyoming. North Carolina-based Duke was sentenced in 2013 to $1 million in fines and restitution and five years probation after the deaths of 14 golden eagles, and a year later Oregon-based PacifiCorp, received $2.5 million in fines and five years probation for 38 eagles killed.
Minimize eagle deaths
The number of wind turbines nationwide has more than doubled in the past decade to nearly 72,000, according to data from the US Geological Survey.
To control the impact on eagles, federal authorities want companies to obtain permits allowing them to kill certain birds if the deaths are compensated. The companies then pay the utilities to retrofit the utility poles, so the eagles can’t be easily electrocuted. Each 11 upgraded poles generally counts as an avoided eagle kill.
Across the country, 34 permits last year allowed companies to ‘take’ 170 golden eagles – meaning many birds were killed by turbines or lost due to impacts on nests or habitat . A review of Associated Press public records shows that most are wind farms.
“It sounds crude, but it’s realistic. Eagles are going to be accidentally killed at wind farms,” said Brian Millsap, who leads the wildlife service’s eagle program. “We need to reduce other things that will allow the development of wind power.”
The nests where Bedrosian and Preston are conducting population surveys are about 60 miles from the nearest wind farm — 114 turbines that PacifiCorp began operating about two years ago near the Wyoming-Montana border.
On-site staff scan the sky with binoculars for eagles and can shut down turbines as they approach. Ten PacifiCorp wind farms have permits allowing the accidental killing of eagles, according to the company.
Company representatives declined to say how many eagles have died at these facilities. They said PacifiCorp had built a “bank” of retrofitted hydro poles to compensate for eagle fatalities and also wanted to try new approaches such as painting turbine blades to make them more visible and easier to avoid.
“We work as hard as we can to avoid and minimize (fatalities) up front, and then anything we can’t, we mitigate at the back,” Brown said.
The Associated Press Health and Science Department is supported by the Howard Hughes Medical Institute Department of Science Education. The AP is solely responsible for all content.