Work underway to thin overgrowth along a 7-mile stretch of NStar transmission lines in Middleborough includes some special precautions for about four dozen of the town’s most vulnerable residents.
For the past five months, state officials, environmental advocates, and the utility company have staged a kind of “turtlepalooza” along Row 280, the utility’s 16.7-mile transmission line from Carver to Bridgewater.
There, in the middle of the line, in the heart of Middleborough — a town the utility doesn’t even serve – lies a large population of the Eastern box turtle, a species considered of “special concern” to the state.
Since May, at least 42 of the terrestrial creatures have been located along the line and fitted with micro transmitters so their movements can be monitored on demand as work progresses, said NStar spokesman Michael Durand.
Contractors will be taking down trees and cutting branches on the roughly 30-acre woodsy easement that backs up, in many cases, to private homes, according to Durand.
The vegetation-clearing effort is necessary to ensure reliable service, he said.
According to a permit issued by the Massachusetts Division of Fisheries and Wildlife’s Natural Heritage and Endangered Species Program, NStar must not only train workers and contractors to spot and protect the turtles, it must also donate $136,000 to The Nature Conservancy to help protect them.
“This goes beyond the requirement of protection,’’ said Durand, of his company’s project, which could run through year’s end.
Because so many turtles are found at NStar work sites in Eastern Massachusetts, Durand said the company is committed to working closely with state agencies to protect them. The utility company must do its work, he said, but it also wants be a good neighbor and coexist well with others on land where species are endangered.
Durand said he couldn’t estimate how many trees will have to come down during the project. A similar effort in Duxbury last spring upset many residents, who complained that the line clearing – which involved hundreds of mature trees — slashed the buffer to private property.
Middleborough residents are also concerned about their properties, said the town’s conservation agent, Patricia Cannady. “I’ve had calls from neighbors in the Cottonwood Development who are upset the trees are coming down,’’ she said.
The town’s Conservation Commission is also concerned about the trees and whether the NStar donation will be used locally for habitat protection, and it has sent a letter of inquiry, she said.
Eve Schluter, a senior endangered species review biologist with the state’s Natural Heritage program, said Middleborough’s turtle habitat is definitely a “hot spot.” Education and training go far in ensuring that utility crews know what they are looking for, she said.
Because of that, “we’ve had success in minimizing the effect of the work on turtles,” Schluter said. “This species, and turtles in general, are at risk for a lot of things.’’
The Eastern box turtle can live up to 100 years under ideal conditions, she said. Many, though, fall victim much sooner to encroaching development and vehicle traffic.
NStar and consultant Oxbow Associates of Acton went on a mission from May to September to locate the turtles and affix the wireless devices to them. Four nests were equipped with predator enclosures and removed to incubators in mid-August in advance of hatching, and then the hatchlings were released in early September, officials said.
Contractors have been given 24-hour cellphone contacts if a turtle is found while the cutting is ongoing, said Oxbow president Brian Butler, in supplemental instructions to the permit.
Laminated posters about the turtles are also displayed at work sites, according to the permit, to help with identification.
Turtles deemed to be in jeopardy, or too close to work areas, will be collected and stored in a 5-gallon pail until the coast is clear, officials said. Any that must be detained for more than 72 hours will be placed in a locked steel cage, which will be chained to a large tree and covered with leafy materials. If an exam shows a loss of more than 1 percent of body fat while captured, the animal will be hydrated for 30 minutes prior to release.
In an interview, Butler said the Eastern box turtle population is affected by even a small loss of adult animals. He estimated the statewide population as in the thousands, but not the tens of thousands.
“For the first 200 million years of their lives there were no cars or obstacles,” he said. “Now, if you take one or two out every year, or even every three years, the population very soon would be doomed.”
Everyone loves turtles, Butler said, and even the biggest lineman will sit down and tell his snapping turtle story during trainings.
Middleborough Selectman Allin Frawley said he is “ecstatic” that a company like NStar took it upon itself to help an endangered species.
“I’m the guy that stops traffic to help turtles cross the road, or I carry them across the road,’’ he said. “But I always hope that I moved them in the direction they wanted to go.”