Golden Eagles and Wind Farms


Golden Eagles and, to a slightly lesser extent, Bald Eagles are the true kings of the North American skies. Sure, other birds will mob them sometimes, if they think the eagle is targeting their nests, but eagles are apex predators; they own the skies.

Golden Eagle on a Nest, Alaska Range

Golden Eagle on a Nest, Alaska Range

Except that wind farms are thickets of high speed guillotines, the big turbine blades a mortal hazard to all birds, and perhaps especially big raptors. Eagles are highly intelligent birds, but wind turbines and spinning blades are utterly new, and encounters are usually fatal. There’s precious little opportunity to learn to avoid them.

This isn’t a screed against wind turbines; as WC has written elsewhere, you have to weigh consequences in assessing any energy source. But it’s also possible to reduce the carnage.

Recently, the U.S. Fish & Wildlife Service has used to Migratory Bird Treaty Act to prosecute two energy companies for Golden Eagle kills. In both cases, the energy companies have plead guilty under negotiated pleas.

On December 19, 2014, PacifiCorp Energy entered into a criminal plea agreement under the Migratory Bird Treaty Act (MBTA), for deaths of golden eagles and other migratory birds at wind energy projects in Wyoming. The plea came a little more than a year after Duke Energy Renewables signed the first-ever MBTA criminal plea agreement for a wind turbine facility, also for projects in Wyoming.

Duke Energy admitted it killed 163 migratory birds, including 14 golden eagles, at two projects – Campbell Hill and Top of the World – between 2010 and 2013. The Duke Energy settlement also included commitments, but no criminal charges, involving two other wind farms where some migratory bird deaths but no eagle deaths had been reported.

Eagle killed by wind turbine, photo by U.S. Fish & Wildlife

Eagle killed by wind turbine, photo by U.S. Fish & Wildlife Service

The PacifiCorp plea was based on the mortality of 336 migratory birds, including a very troubling 38 golden eagles, at two projects – Seven Mile Hill and Glenrock/Rolling Hills – between 2009 and 2014. Like Duke, PacifiCorp’s plea agreement also included commitments, but no criminal charges, for two other wind farms, but unlike Duke, those other two projects involved six more eagle kills.

While two cases are a tiny sample, the PacifiCorp settlement suggests that the 2013 Duke Energy plea bargain was not an anomaly and that the U.S. Fish and Wildlife Service’s enforcement initiative is likely to result in additional cases, also focused on the deaths of golden eagles at wind energy projects. There are similarities between the two plea agreements that suggest the USFWS wants to have a template for tbose possible future settlements.

The terms of the two plea bargains have parts that please and parts that appall birders. In each of the plea agreements, the company admitted to two class B misdemeanor violations of the MBTA for the unlawful take of migratory birds, agreed to pay a fine of $200,000 for each violation and agreed to be on probation for five years.

The companies also agreed, as specific conditions of their probation, to:

  1. Pay restitution to the state;
  2. Make “community service” payments for eagle conservation;
  3. Comply with a Migratory Bird Compliance Plan negotiated with FWS;
  4. Apply for Eagle Take Permits; and
  5. Pay compensatory mitigation for future eagle mortalities.

It’s the third and fourth points that trouble conservationists. The Migratory Bird Compliance Plans involve things like observers who, spotting migrating birds, can order the turbines to be shut down. But while raptors mostly migrate by day, most songbirds migrate by night, when observers are useless. And the obvious implication of “Eagle Take Permits” – licenses to kill eagles with wind turbines – are troubling.The American Bird Conservancy is unhappy enough that it has filed suit against the USFWS.

The devil is always in the details. An “Eagle Take Permit” that allows the accidental killing of a handful of birds a year might be permissible; a number of “Permits” that in total allow the killing of the birds at level above that at which net reproduction can sustain the populations is indefensible. The science in the area – even the extent to which eagles follow narrow “corridors” in migration – is murky and incomplete. Where you don’t have data, you have to be especially cautious. And there isn’t much data.

As just one simple example, eagles in migration fly differently when there are strong thermals than they do when the air is calm. Strong thermals favor high flight. Calm air or head winds make eagles fly lower, hugging ridges. There’s even some slight evidence that in migration eagles will sometimes avoid wind farms. But eagles in migration also have to hunt and, when hunting, they are closer to the ground and looking down, not ahead. The potential for injury is much higher. It’s complicated, and there is precious little data.

Wind turbines the only man-made change to the eagles’ environment. If you’ve flown over the western half of the United States in recent years on a clear day, you have seen the staggering number of wind farms that have been constructed, and the size of the larger ones. But high tension power lines, poorly designed power poles, habitat loss and climate alteration have also impacted eagles. Eagle Take Permits based on wind turbine kills alone are a badly flawed, incomplete solution.

Nor all birds of equal concern. A flock of Eurasian Starlings – an invasive, common and highly successful species – is different than a flock of Red Knots – a badly endangered, very seriously threatened shorebird. But because a distant flock of birds is, well, a distant, unidentified flock of birds, it’s difficult to do anything but shut the turbines down when the flock approaches. Migrating birds don’t wear identification labels.

Golden Eagles are of special concern because they reproduce very slowly. The species doesn’t breed at all until a bird is five years old or older. The whole process – nest-building to fledging – takes about six months, and even then the new kids remain dependent on the parents for another 2.5 months. Even in a good year the parents may fledge only one chick. And survival in young birds is always low.

We already know that Duke Energy doesn’t give a damn about the environment. It respects the environment only to the extent that the Feds make disrespect unprofitable through fines and criminal prosecutions. If Duke Energy and Pacific Energy don’t care about massive ash dumps in rivers, you can be very certain they don’t care about a few dead birds.Those companies will want their “Eagle Take Permits” to be at least as high as the bird numbers they’ve already killed. The American Bird Conservancy and WC want it to be as close to zero as possible.

There is a cost to any source of electricity. And the cost always includes damage to the environment, even if those costs don’t appear on Duke Energy’s financial statements or shareholder dividends. The environmental cost needs to be held as low as possible and, in the case of species of concern, like Golden Eagles, near zero. Anything else is crooked accounting.

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