If you have an elk, deer or antelope tag in certain areas of southeast Wyoming, researchers want to give you free ammunition.
That’s right. For two years, about 700 hunters in Shirley Basin may qualify for free, non-lead ammunition as part of a study paid for by the National Fish and Wildlife Foundation’s Wyoming Golden Eagle Fund.
All researchers want to know is if you used the ammunition and if you successfully filled your tag.
This isn’t your average non-lead ammunition study. Scientists don’t need a lot more data in Wyoming showing how lethal lead fragments are to eagles and other raptors who scavenge off of carcasses. No, this study is designed to see if hunters using non-lead ammunition can offset deaths caused each year by wind turbines.
Let us explain. Wind turbine companies are required to offset the number of eagles they kill each year, but right now the only way to do that is by retrofitting power lines to cut down the number of eagles electrocuted. Federal regulators want to see if other options exist, and Shirley Basin, with a high concentration of hunters, big game, eagles and wind turbines, is one of the best places to look, said Ross Crandall, executive director and research biologist with Kelly wildlife research firm Craighead Beringia South.
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“We absolutely know that lead does kill golden eagles. We know if we decrease the lead on the landscape, it will decrease eagle mortality, but how much lead can we get out of there to have a substantial impact,” Crandall said. “We‘re not necessarily focused on reducing lead mortality period, but focused on whether this provides an opportunity to offset wind farms.”
Lead, turbines and eagles
First, a little background on lead.
When a hunter shoots an elk, antelope, deer or other big game animal with a lead bullet, the bullet explodes into hundreds of fragments stuck throughout portions of the creature’s insides. Researchers have taken slow motion video of the process, illustrating how much lead – which may be nearly invisible to our naked eyes – remains.
Eagles, hawks, coyotes and other scavengers then feast on the carcasses often leaving only a scattering of bones behind to bleach in the Wyoming sun.
But eagles are particularly susceptible to lead poisoning. Even small concentrations impair an eagle’s ability to react to threats like power lines and wind turbines. It also changes an eagle’s ability to hunt effectively, leading to starvation instead of actual lead poisoning.
A study out of Jackson about 10 years ago showed that offering hunters non-lead ammunition during hunting season did, in fact, lower the amount of lead in eagle’s blood.
While golden eagle numbers in the U.S. never crashed like bald eagles, researchers are concerned the numbers are dropping.
Lead is far from the primary culprit. Wind turbines, electrocution, car collisions, shootings and starvation rank high on the list, according to the U.S. Fish and Wildlife Service.
Work is being done to retrofit power poles, and researchers have even talked about moving carcasses from roadways to reduce the number of eagles hit by cars – their crops so full of meat they can’t fly out of the way fast enough. Retrofitting power poles works well, Crandall said, but when mitigation work must be done in the same area as the wind farms, only so many miles of power lines are available to retrofit.
Ideal corridor
As far as areas to try this kind of experiment, few places exist better than Shirley Basin nestled up against the Laramie Range in southeast Wyoming.
Golden eagles live there year round, feasting on ground squirrels, prairie dogs and rabbits in the spring and summer.
Then those birds, along with a huge influx of wintering golden eagles, spend the fall munching on carcasses killed most often by hunters and vehicles.
“That unfortunate timing of when the eagles are shifting their feeding behavior and this new food source on the landscape is overarching as we think about our project,” said Vincent Slabe, a research wildlife biologist with Conservation Science Global, Inc.
Additionally, the Wyoming Game and Fish Department offers about 3,500 limited quota deer, elk and antelope tags in the area each year. Those factors, combined with the ever-increasing number of wind turbines taking advantage of a consistent breeze, and it’s the best place for this kind of study, Slade said.
Nonlead ammunition is a touchy subject in the nation’s hunting community. Some environmental groups have called for a ban. Shooting associations say it should be up to the hunter to switch, and often question the actual impact of lead fragments in carcasses.
But Crandall and Slabe aren’t interested in policy or mandates. They just want to know if giving hunters free ammunition could save eagles as a data point for federal and state wildlife managers and wind companies.
The two-year grant comes from money collected from fines associated with eagle deaths at two Duke Energy wind projects in Wyoming. Slabe and Crandall partnered with Selway Armory out of Montana to offer nonlead ammunition.
“The bottom line is,” Crandall said, “is does it make financial sense? If it does, our goal is to use this effort and provide a cookbook or set of instructions saying this is how it worked, how many people to expect to take advantage of it, how many animals you can expect to have harvested and how many eagles you expect to have saved.”