Ospreys evicted from power line; are chronic problems
BY Sarah smith
A pair of ospreys that decided to nest overlooking the Itasca-Mantrap substation in Hubbard County was recently sent packing after power company officials found them to be a hazard.
In July, the pair began erecting a nest of sticks, sod and manure at the intersection of Hubbard County Roads 4 and 40 on a pole owned by Great River Energy. This is a fairly common occurrence, said GRE spokeswoman Lori Buffington.
“Pieces of the nest can fall onto the wire and break insulators,” Buffington said. “It poses a safety issue for people performing maintenance on the line and it can cause an outage.
“We want people in the community to understand when osprey build their nests on our equipment it creates a hazardous situation and we need to remove them.”
With energized equipment, the situation is always dangerous, she said.
Sticks from the nest falling onto substation equipment can also cause a fire.
The pair started building in July. Although from the ground, the pole up the middle wasn’t visible, the pair seemed crowded onto one side of the nest.
“It did not have eggs in it,” Buffington said. “It was the start of an osprey nest. There was actually no room for nesting because the pole was sticking up through the middle of it.”
According to the Cornell School of Ornithology, ospreys start small and, over a decade, add on so nests become monstrous.
Starting nests are around two feet, which this one was. Males choose the site and begin gathering dead twigs from neighboring trees.
The females build the nest.
“Ospreys are excellent anglers,” the ornithology website says. “Over several studies, ospreys caught fish on at least 1 in every 4 dives, with success rates sometimes as high as 70 percent. The average time they spent hunting before making a catch was about 12 minutes.”
The birds have barbed pads on the soles of their feet to keep slippery fish in their grasp.
The Mantrap substation is near Big Sand Lake, but does not overlook water.
Building platform nests on manmade structures has been instrumental in re-establishing the raptors in areas where they previously disappeared, Cornell bird experts maintain.
After a generation of nesting, the abodes have grown to six feet in diameter and up to 10 feet deep.
Because the birds are fish-eaters, Cornell says they generally nest within 12 miles of water.
Cornell says the birds lay between two and four eggs and they hatch five or six weeks later in the order they were born.
The oldest chick is dominant and usually hoards the food, which is why so many younger siblings don’t survive.
Buffington said GRE generally works with the DNR in removing nests.
“A permit was not required in this case,” she said. “We work closely with the DNR to receive the proper permits when we need to remove nests but when the hazard is only the beginning of a nest the DNR’s been clear that a permit is not required.
“In some areas we do have cases where osprey do build their nests on our structures,” she emphasized. “It is fairly frequent. We want people to understand why we have to remove them and we also understand the community’s appreciation for the bird.”
The avian interlopers won’t be back.
“In its place our crews installed a nest deterrent,” Buffington said. “Those are things utilities use to ensure the birds nest somewhere else so we can avoid problems in the future.”