​Removing raptor nests for reliable transmission​

By Aidan Wiese

With big eyes and sharp talons, one might think that ospreys don't need much protection from anything. However, these large raptors were once considered an endangered species due to DDT pesticide poisoning in the 1950s and 1960s.

Though the birds have made a substantial comeback today and can be found on every continent except Antarctica, osprey nests that wind up on transmission lines can cause damage not only to the line and surroundings, but to the birds themselves, making their removal critical for WAPA, customers and the formerly endangered species alike.

These birds often build large nests with thick sticks, and often build on human-made platforms because they prefer to nest in areas without overhead foliage. Unfortunately, this makes transmission lines appealing real estate prospects for the ospreys.

On Sept. 8-10, WAPA's Craig, Colorado, line crew and other supporting crews, including Helicopter Pilot Rory Kirkendall, removed several osprey nests and installed perch discouragers on the Windy Gap-to-Granby Pumping Plant No. 1 and No. 2 double-circuit transmission line in Grand County to improve reliability for the line and help protect the birds.

The perch discouragers were ordered the previous winter in anticipation of and preparation for installation after the end of the 2021 nesting season. This work was performed by helicopter with biological monitoring provided by Natural Resource Specialist Mark Suchy.

"The name perch discourager is a bit of a misnomer," said Suchy. "They're really breeding and nesting discouragers, as opposed to the traditional perch discouragers. Traditional perch discouragers often look like little spikes, and the ones we installed on this project look less intrusive and dangerous."

The line had recently been rebuilt with monopoles, and with the food-rich environment around Lake Granby, Shadow Mountain Lake and Grand Lake it was only a matter of time before the raptors moved into the unintentionally perfect nesting spots atop the lines.

Complicating the matter further, ospreys can use a variety of materials when building their nests, and carry prey materials to their nests, which they will return to for up to 25 years.

As the birds nest and perch on the structures, there's also the possibility for streamers - lines of bird excrement - that can form an alternate pathway for electricity to flow through. With these issues, allowing the birds to continue using the structures for nesting platforms would pose further risk not only to the ospreys, but also to the safety of the linemen and the power system itself by causing a potential interruption, outage or even a fire.

"The original intent of perch discouragers was to prevent the birds from perching on a surface," said Environmental Protection Specialist Andrea Severson. "However, some of the older designs sometimes made it easier for birds to nest and helped create nesting problems. The cones we use now not only help discourage perching but also help discourage nest placement."

"This is a balancing act between preserving the integrity of our grid and not being too disruptive to the birds, and I think we did a great job," said Suchy. "We wanted to be good stewards, so we waited for the optimal time to remove the nests: after the osprey breeding season."

Adding the perch discouragers adds to the reliability of the grid in the area.

"The structures are near the western entrance of the Rocky Mountain National Park and are highly visible to residents and tourists, so the results of our cross-department efforts are in public view," Suchy continued. "It's a continuous collaboration between all of WAPA's departments to maintain facilities, structures, lines and vegetation to keep our workers, the community and the environment safe."

The good news today is that ospreys are thriving, both in the Grand County area and in the world at large, in no small part due to conservation efforts and avian protective measures.

"When we rebuilt this line, I don't think we fully anticipated the scale of the osprey issue," Severson concluded. "It's been a good learning experience for us so that in the future we can think proactively in terms of reliability and avian protection when our work intersects with the habitat for these birds."

Note: The author is a secretary who works under the Miracorp contract.

Crews, including Lineman Tyler Delay, removed osprey nests and installed perch discouragers in Grand County, Colorado. (Photo by Mark Suchy)

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