TRURO — Of the osprey, Henry David Thoreau wrote, “Its shrill scream seems yet to linger in its throat, and the roar of the sea in its wings.” At the Truro Transfer Station, what lingers are the charred beams at the top of a utility pole where an osprey nest briefly sat this spring.

For years, the transfer station has been host to these birds. On April 20, the tangle of sticks and debris they had assembled at the top of the pole began smoldering. Luckily, no ospreys were home when their nest caught fire, according to Peter Cook, the transfer station supervisor.

The fire dept. responded right away, but the flames put themselves out, said Cook, who was working when the nest began to burn. Once the nest had burned completely, the fire waned. A downpour that day may have helped to put out the fire, Cook said. Still, the circuit breakers blew, and the transfer station lost power. Eversource showed up to restore it.

Later that same night, according to Cook, the birds began constructing a new nest atop the same utility pole. A couple of weeks later, the rebuilt nest was robust: the lattice of sticks stretched a couple of feet in diameter.

On May 6, the power went out again. That time, the nest “didn’t fully catch fire,” said transfer station assistant Dylan Kaeselau, but the breakers still blew. Eversource responded to the scene and removed the nest.

According to Eversource’s osprey management plan, if a nest without eggs or chicks causes a power outage, the nest is to be removed for electrical inspections.

Eversource also installed what’s known as a “deterrent” — a contraption made of polyvinyl chloride designed to prevent ospreys from building nests. The deterrent, mounted on the utility pole, makes it “difficult for a large bird, such as an osprey, to maneuver around the top of a utility pole,” according to Kyle Costa, a media relations specialist at Eversource Energy.

Deterrents are recommended at all sites of nest-born electrical fires because ospreys “have strong nest site fidelity,” according to the management plan. “They will continue to build at a certain location regardless of how many times the nest is removed.”

The power went out again a day later, on May 7, under somewhat mysterious circumstances. With the nest gone, it was not at first clear what had caused a circuit breaker on the highway to blow. Then Cook found what he said was half a charred herring beneath the power lines where the nest had been.

The piscivorous osprey, attempting to deposit the fish into its nest, had dropped it onto a live electrical wire.

On May 12, a new collection of sticks had been placed on the utility pole, now adorned by a narrow PVC beam. More were scattered at the base of the pole, probably dropped there by ospreys attempting to build a third nest.

Ospreys on the Cape

The osprey population on Cape Cod is healthy, which was not always true. It dropped dangerously low in the mid-20th century, according to the osprey management plan. The birds’ ingestion of the insecticide DDT thinned their eggshells, reducing the number of surviving hatchlings. Since DDT was banned in the early 1970s, their population on Cape Cod has been steadily growing, from fewer than five in the 1970s to at least 800 in 2021.

And those birds love utility poles, according to Mass Audubon science coordinator Mark Faherty, “especially the old fashioned ones with two wooden cross arms at the top and then no structures above the cross arm,” he said. “It’s a perfect place for them.”

With the population growth there’s been a corresponding increase in “electric pole-related incidents such as electrocutions, nest fires, and osprey-induced power outages,” according to Costa.

The nests catch fire frequently when “arcing” takes place: an electrical current jumping between two connectors. “A stick bridges two of the live wires, and it catches fire,” Faherty said. Once it does, the nest is essentially “a pile of kindling waiting to catch,” according to Mass. Audubon.

That the transfer station fire happened when it did may have been a blessing, preventing any casualties. “When it happens later in the season, chicks are involved, and it’s just a bad scene,” said Faherty.

Osprey chicks typically hatch in late May or early June.

At the Transfer Station

According to Cook and Kaeselau, the ospreys have relocated to a wooded area just south of the transfer station. “They’re always flying around, so they’re still in the area,” said Kaeselau.

In the past, the ospreys nested on the tiered cell tower just west of the transfer station. Cell towers don’t pose the same electrical threat as utility poles, though telecom companies don’t like birds to nest there “in case it impacts the equipment in some way or hurts cell reception,” Faherty said. “But generally, cell phone tower nests are pretty innocuous.”

Since last year, however, the cell tower spot has been taken over by ravens, according to multiple observers.

Earlier this spring, the ravens and ospreys “were flying around each other up there,” said Cook. “It looked like the ospreys were trying to get into the top of the tower, and the ravens seemed like they were trying to keep them out.”

The ravens’ hijacking of the ospreys’ usual nesting site isn’t typical bird behavior, according to Faherty. Ravens nest earlier in the season, meaning they could have initially settled in the ospreys’ usual spot. That’s been known to happen with eagles, which also nest earlier than ospreys. Usually the ospreys will seize their territory back from the eagles.

“When you consider that ospreys can more often than not successfully fight off bald eagles that are taking over their nest, they should be able to handle ravens,” Faherty said. “I’m not really sure what happened there.”

Indeed, Thoreau also wrote of the osprey that “There is the tyranny of Jove in its claws, and his wrath in the erectile feathers of the head and neck.”

Naturalist Dennis Minsky found the situation less anomalous. “Ravens have so much more brain power than ospreys,” he said. “They would just figure it out, come up with strategies, persist. Ospreys do have talents, but they’re mainly fish eaters.”

The ospreys “are getting more and more used to people,” said Cook. In the past, they would frequently flee when cars entered the transfer station, he said. The early morning, before opening time, was the best for sightings: an avian vortex of ospreys, turkey vultures, and ravens.

Shaun Pfeiffer, a Truro resident, has begun slinging his binoculars around his neck each time he visits the transfer station. “I generally take an interest in the birds that are at the dump,” Pfeiffer said.

There’s a latent affinity at the transfer station for the ospreys.

“They’re like our little mascots,” said Kaeselau. “Little mascots who made their nest on a high-voltage pole.”