Every now and then, good conservation requires a person to hang off a helicopter 100 feet in the air to fiddle with transmission powerlines.
That’s just what ComEd technicians did last week in a coordinated effort with the Forest Preserve District’s Resource Management department. On May 30 and June 4, two helicopters hovered delicately over powerlines running across Tampier Slough, better known these days as the home of Cook County’s first nesting American bald eagles in more than 100 years.
The mission: install bird diverters (what Resource Management director Chris Merenowicz calls “giant curly fries”) on the static lines that protect the live power lines from aerial impacts and lightning strikes. The diverters make the line more visible to birds and prevent them from flying into it.
With adult birds this isn’t as big an issue; the adult eagles at Tampier have been successfully navigating the airspace around the lines for months. Yet the juvenile eagles are now beginning to test out their wings and, with any luck, will soon be making their first tentative flights around the nest. Biologists were concerned that these flyers-in-training would not be so skilled at seeing and avoiding the lines.
And so the two helicopters, equipped with special platforms for the transmission overhead lineman, flew from their launch site in the Tampier Lake West parking lot and hovered over the lines. Each repairman, strapped onto his shelf with a safety harness and something that looks like a seatbelt, guided the pilot close enough to the lines that the repairman could attach a bird diverter every thirty feet or so along the power line.
Although winds picked up on the first day, the helicopters returned for one additional day, logging about 16 hours before the work was finished. ComEd installed more than 450 diverters along roughly 6,000 feet of powerline, as far as a half-mile away from the eagle nest. The diverters will benefit many other birds in the avian-rich location as well, including osprey, herons, hawks, and others.
On the first day of the installation, Forest Preserve District wildlife ecologists paddled a canoe out to the far shore of Tampier Slough to monitor the nest, ready to respond in case the juveniles reacted negatively to the helicopters hundreds of yards away.
But the eagles showed little signs of disturbance. The adults continued to fish and feed the young as the helicopters approached. Then they flew to trees with a good view and kept an eye on the helicopters the entire time. The young remained in the nest. As of this week, the eagle family is continuing its business of tending the young and trying some pre-flight flapping.