There’s a promising new technology to help protect crane species around the world, and the solution to reducing their midflight accident deaths may be as simple as shining UV lights on the power lines that are killing them.
That’s according to researchers at EDM International, a power utility and environmental services company in the United States, who developed an Avian Collision Avoidance System that relies on ultraviolet light beams to which the birds are especially sensitive. They think the ACAS helps the birds to see power line markers and avoid the lethal consequences.
The EDM study results, published in The Condor: Ornothological Applications, showed a remarkable 98 percent reduction in power line collisions for sandhill cranes, which have a North American range from Mexico to Canada.
EDM research engineer James Dwyer said the project began after years of studying the birds’ collisions with power lines. These midflight collisions affect 12 of the world’s 15 crane species, which include one critically endangered crane, three that are listed as endangered and five that are considered vulnerable.
Dwyer and his colleagues knew that hundreds of sandhill cranes died each year in the U.S. state of Nebraska, where the Iain Nicolson Audubon Center at Rowe Sanctuary is a major migration destination. So they tested their theory on a 258-meter line that stretches across the Central Platte River near there, mounting the UV lights on support structures and comparing the collision rates when turned on or not.
On 19 nights when the ACAS was turned off, there were 48 collisions and 217 dangerous flights – defined, the scientists said, by the evasive maneuvers of the birds and proximity when they used them.
When the UV lights were turned on, also for 19 nights, they witnessed only one sandhill crane collision. There was a 32 percent drop in evasive flight maneuvers when the birds were within 25 meters of the power line, at the same time there was a 71 percent increase in the maneuvers from farther away.
“Sandhill cranes reacted sooner and with more control, and experienced substantially fewer collisions, when the ACAS was on,” said Dwyer, the lead author for his team. “Installation of the ACAS on other high-risk spans, and perhaps on other anthropogenic obstacles where birds collide, may offer a new solution to a long-running conservation dilemma.”
Dwyer said they need to see how the UV light affects the cranes’ mortality on lines that don’t have bird markers, though about half of the ones in use at the Nebraska site have glow-in-the-dark stickers so the birds can see them at night. They suspect the light makes it easier to see the line markers – a common conservation mechanism in the industry – but not all power lines have them.
They’re also not sure how the findings might affect other birds. The U.S. Fish and Wildlife Service says there are up to 185 million poles in the U.S. alone, and up to 57 million bird deaths from collisions with electric utility lines. Obviously the cranes aren’t the only ones affected, nor are power lines the only problem.
“Electric utility infrastructure continues to increase,” the service said. “Resolving conflicts between birds and power lines continues to be an important focus of bird conservation efforts both in the U.S. and around the globe.”