Wildlife authorities and utility officials have been taking aim at one of the leading killers of bald eagles in New Jersey -- electrocution on power lines.
There is growing concern about protecting the endangered birds from getting electrocuted by power lines when they nest in suburban and urban areas following a spike in the eagle population, The Philadelphia Inquirer reported. Between 2015 and 2019, electrocution was the top cause of death of raptors found injured or killed, according to data compiled in annual reports by the New Jersey Bald Eagle Project, a partnership overseen by the New Jersey Division of Fish and Wildlife and Conserve Wildlife Foundation.
In addition to the 34 eagle deaths, crashes into vehicles left 29 eagles dead and fights with other eagles killed 14. The cause of 29 other deaths remains unknown, and officials say some deaths are undocumented.
Kathleen Clark, supervising zoologist for the state's Division of Fish and Wildlife, said an electrocuted 4-year-old eagle was found on a recent Sunday near Pickle Factory Pond in Belleplain State Forest.
"We've known that that's an eagle area for a long time," Clark said.
She said the eagles are vulnerable because of their large wingspan, which can reach six or seven feet. Officials say a talon touching an energized line and a wing touching another or a ground source sends electricity through the bird and is usually fatal.
"In general, electrocution is difficult to treat because the extent of the damage is not always immediately apparent,'' said executive director Lisa Smith, of Tri-State Bird Rescue & Research in Delaware. Over the past two years, the center has received six eagles thought to have been electrocuted, and three were dead on arrival and three were "humanely euthanized,'' she said.
Officials say large transmission lines and poles are less dangerous because wires are spread out more, but smaller distribution lines the birds perch on for hunting and other reasons are more likely to prove lethal.
Cristina Frank, a biologist and raptor specialist who manages avian protection for Atlantic City Electric, said utilities can't realistically bury all distribution lines, so they install protective equipment or build-in protections on new lines. The measures can include cross-arms on existing lines to spread wires farther apart, insulated conductors, or covering energized or grounded equipment. Some utilities also install barriers to prevent birds from perching and mark lines with colored tape or reflectors to warn birds from flying into them.
Frank said the company has compared distribution line maps with GPS tracks from banded birds to see which equipment is near bald eagle habitats, identifying 80 new eagle roosts and 21 line segments with potential risk of collision. In some cases, she said, the company has rebuilt lines to be more bird friendly.
Project manager Claudia Rocca of PSE&G said her company also retrofits equipment to increase safety for the eagles. Pole-top extensions have been added onto distribution poles frequented by eagles so the birds can safely perch away from the lines, Rocca said. Clark said she believes such measures are already having an impact.
"To do nothing would be to leave all these known risks out there on the landscape,'' she said.