During spring migration, more than a half-million Sandhill Cranes concentrate along the Platte River in central Nebraska, a critical stop-over area where cranes have fed and roosted for thousands of years. Unfortunately, every year, dozens to many hundreds of Sandhill Cranes suffer deadly collisions with two electrical transmission-lines that cross the Platte River at Audubon’s Rowe Sanctuary. But recently, a biologist tested a new method that reduced crane-fatalities at the property by 98 percent. If his results can be expanded to other sites, the technology will offer a new way for the industry to address a hazard that kills many millions of birds annually in the United States alone.
James Dwyer, a scientist who helps electric utilities build more bird-friendly infrastructures, embarked on the research because he saw that a key practice for trying to prevent accidents — the use of reflective, glow-in-the-dark, or similar kinds of markers on the wires — wasn’t effective after the sun went down. “It was clear to me that the industry standard was not having a sufficient effect,” he explained.
With engineering colleagues at EDM International, the utility-technology company where he works, Dwyer developed what he dubbed an “avian-collision-avoidance system.” The system is actually rather simple: It’s a solar-powered device fitted with ultraviolet lights that shine on the wires when mounted on transmission poles. The goal was to make the power-lines more visible to birds, while trying to avoid light-pollution complaints from neighbors. “We went with UV light because birds can see it and people can’t,” explained Dwyer.
Though he wasn’t certain that Sandhill Cranes could see the shorter light-waves, more studies are showing a wide range of birds, from storks and puffins to loons and owls, have eye structures that detect violet or ultraviolet light-frequencies. Based on this, Dwyer launched his experiment in spring of 2018. The results exceeded his expectations.
After the utility company, Dawson Public Power, gave the go-ahead to test the system at Rowe Sanctuary, a technician monitored a single 850-foot span of power-lines on the property for 19 nights with the UV lights turned on and 19 nights with the UV lights switched off.
The team reported that the Sandhill Crane collision tally dropped from 48 in the nights without UV lights to only 1 collision with the lights turned on. What’s more, the number of “dangerous flights,” when a flock of cranes flew near the line and didn't stop or swerve, also decreased 82 percent, from 217 to 39 instances. The researchers also noticed that more birds changed their flight-path when they were more than 80 feet away from the line, giving them adequate clearance-room to avoid a brush with death.
At Rowe Sanctuary, the power-lines are already fitted with colorful coils and hanging tags that have reduced some crane-fatalities, but some collisions occur either during foggy weather or at night. Sanctuary Conservation Director Andrew Pierson was impressed by the new results: “It seems quite positive,” he said, “It seems like it worked.”
Sanctuary staff are already meeting with Dawson Public Power about options for reducing crane-deaths, including bigger steps like burying the power-lines underground or repositioning them to a less-sensitive location. If the new collision-avoidance technology becomes available, Pierson is optimistic the utility will consider utilizing it. He noted that it could also help endangered Whooping Cranes to avoid the power-lines while passing through Platte River habitats.
“[The utility] is worried about collisions, too, especially collisions regarding an endangered, listed species,” Pierson added. “This represents a fairly cheap opportunity.”
While the results are promising and offer a new preventative approach, more testing is required to demonstrate that UV lights work broadly for other birds and locations, says Richard Loughery, director of environmental activities at the Edison Electric Institute. He helps coordinate the Avian Power-Line Interaction Committee, an industry group that collaborates with wildlife and conservation managers to fund research, work on power-line-siting issues, and publish protocols for avoiding bird-collisions and electrocutions. The Aldo Leopold Foundation, for example, turned to these guidelines to win strong preventative measures, including lower towers and the use of line-markers, on a new transmission project near its Leopold-Pine Island Important Bird Area in Wisconsin, said the organization’s Conservation Director Steve Swenson.
Another open question is whether UV lights can be a substitute for line markers, or whether the two methods need to be paired up, like in Dwyer’s study. Installation of line markers can require a helicopter and talented personnel, so it isn’t cheap or easy, Dwyer explained. Less expensive options, such as the UV lights, could help utilities to monitor and protect more birds at a wider range of sites than they do today. That’s the upshot that Dwyer is striving for: “It can solve both the biology problem and the industry problem.”
Dwyer and his associates published their research in The Condor: Ornithological Applications, entitled "Near-Ultraviolet Light Reduced Sandhill Crane Collisions with a Power-Line by 98%" by James Dwyer, Arun Pandey, Laura McHale, and Richard Harness, The Condor, Volume 121, Issue 2, May 2019, which you can refer to at https://academic.oup.com/condor/advance-article-abstract/doi/10.1093/condor/duz008/5476728?redirectedFrom=fulltext.
For more information you can refer to the original publication at https://www.audubon.org/news/a-simple-technology-could-help-stop-birds-colliding-power-lines.
