BPA completes rare relocation of bald eagle nest built on transmission infrastructure

Revered as the national bird of the Unites States, bald eagles receive federal protection under the Bald and Golden Eagle Protection Act and the Migratory Bird Treaty Act of 1918. It is a rare opportunity for humans to interact with bald eagles. The opportunity to preserve their nests is rarer still.

The Bonneville Power Administration had a chance to take part in that exact kind of remarkable opportunity last fall. Collaborating with the U.S. Fish and Wildlife Service and Hanford Mission Integrated Solutions, BPA relocated a bald eagle nest built on a transmission line structure near BPA’s Hanford Substation.

The nest belonged to a breeding pair that originally nested in a snag, or dying tree, about 200 feet away from Hanford Substation. After the snag fell in a summer storm, the eagles began building their new nest on the catwalk of a nearby transmission line structure. Brenna Blankenship, biological scientist for BPA’s Pollution, Prevention and Abatement team, said Hanford Substation employees first noticed the new nest appearing in October 2024.

The nest’s location posed a safety risk to both the eagles and the BPA transmission line maintenance crew responsible for maintaining the infrastructure. The tower’s unusual height and location added further challenge. As a river-crossing structure, meaning the line attached to it extends over the Columbia River, it is taller than a typical structure to allow for proper clearance over the water.

“The catwalk is used by TLM crews to access the structure and is near to where the conductors connect to it, so the nest presented safety concerns for both the TLM crew and the eagles,” Blankenship said.

The nest relocation process consisted of several steps. First, BPA needed to obtain proper permits from the U.S. Fish and Wildlife Service. BPA’s Tri-Cities TLM crew then built a new platform for the nest, situating the platform on a safer part of the transmission structure. Finally, the line crew moved the original nesting material from the catwalk to the new platform in hopes that the bald eagle pair would safely and comfortably redirect to their new nest location.

“We’ve done a lot more relocations of osprey nests,” said Shawn Barndt, BPA’s environmental district lead for the Tri-Cities area. “We have a lot more experience dealing with those kinds of relocations, but because there are so many laws and restrictions about eagles and their nests, this was a trickier process,” he said.

The permitting and planning process to move an eagle’s nest is extensive and rarely undertaken by BPA. Blankenship had the difficult task of navigating the permit application process. Several different online applications for permits exist regarding coming into direct contact with an eagle nest, and the details included on an application are crucial to justify a nest’s relocation. Since reasoning boiled down to safety and operational purposes, Blankenship filed a general nest take permit application for a human-engineered structure.

“There was a lot of correspondence with the USFWS about the problems associated with the nest’s location,” said Blankenship, who also worked with the Hanford Mission Integration Solutions, to apply for all required permits. “The USFWS and HMIS were able to guide us through the process, advising us of what permits we would need to obtain.”

Once the USFWS approved the application to remove the nest and relocate the materials, the physical process of relocating the nest began in December. The Tri-Cities TLM crew, led by lineman foreman III Toby Cossairt, started by building a 4-by-6-foot wooden platform in a safer, lower section on the transmission structure. “I think the crew had a good time keeping an eye on the eagles while they were building and placing the platform, while the eagles were watching from a tower just downriver,” Cossairt said. The team then moved the original nesting material onto the new platform.

“The transmission structure is about 240 feet tall,” said Barndt. “The catwalk is located about where the conductors make contact with the structure, which is extremely high up. The process to build the new nest platform, which is still at a considerable height and about two-thirds of the way up the structure, required hard work and ingenuity.”

To ensure the elevated platform remained habitable for the eagles, the Tri-Cities TLM crew added wooden sides to hold the nesting material in place in the event of high winds. The crew also placed bird diverters, or spiked structures meant to keep birds away from the catwalk, where the eagles originally began building their second nest.

“I was hopeful that they would take to the new nesting location, but eagles are wild animals,” Blankenship said. “You never know if they would find that new location suitable or not.” Luckily, the breeding pair settled into their nest on the platform quickly, despite any disturbance the relocation may have caused.

Since the nest’s relocation, the eagle pair completed a full nest on the lower platform and laid two eggs. Blankenship, who was pleasantly surprised by the speed at which the eagles adapted to the relocation, said that eggs in the nest are a very good sign. “I was hopeful, but wasn’t anticipating that they would lay eggs this year due to the disturbance,” she said. “They proved me wrong and fully took to it. Hopefully, the eggs will hatch, and the chicks will fledge in that nest. It’s really gratifying to know that all that heavy lifting to do this relocation was due to collaboration with our line workers. They created this nice, cozy home for the eagles.”

Moving forward, Blankenship and peers at HMIS will monitor the nest and eggs to ensure their long-term success. Both Blankenship and Cossairt are hopeful that the next step for conserving the eagles will be to construct an independent structure away from the transmission tower.

“We are now hoping to get the go-ahead to build a more permanent nest platform closer to the old tree the eagles nested in for several years before it was blown over in one of our windy storms,” Cossairt said. However, all such considerations are on hold until the end of eagle nesting season in late August.