How much does one Southold Town homeowner care about keeping fencing for endangered bird species’ nests off their beachfront property? Enough to threaten to kill an environmentalist to keep them away, according to an allegation made at Tuesday morning’s Southold Town Board meeting.

The reported threat, while extreme, is emblematic of some residents’ reaction to the environmentalist’s work for the town, said Group for the East End vice president Aaron Virgin, who had been hired as a contractor.

“The rhetoric has kind of ramped up,” he told The Suffolk Times after the meeting.

Mr. Virgin and environmentalist Christine Tylee have been working to set up string fencing on properties to protect where piping plovers and terns nest. The fencing to protect the birds’ nests is voluntary on private land.

The birds tend to nest in sandy areas with little vegetation, and find their way onto town property during most years.

But a harsh winter that killed off vegetation on private lands coupled with delayed beach maintenance by the town this summer season has led the birds to settle down on homeowners’ properties, which were cleared of debris.

There are 20 sites across Southold Town the contractors are monitoring, and most residents are helpful or at least understanding, Mr. Virgin said.

“I think the key word is compromise,” he said, noting the birds — especially the more aggressive terns — have been disruptive to some vacationers.

But the environmentalists have run into opposition from two specific neighborhoods: Breakwater Beach in Mattituck and the houses around Kenny’s Beach.

Ms. Tylee said one homeowner — who was not identified— contacted an attorney who threatened to sue both her and the Group for the East End if she came on the property again. The homeowner later allegedly said he’d kill Ms. Tylee if she set up the fences.

Some seated in Town Hall for the meeting gasped at the allegation. The contractors agreed to document the incident, in case it escalates, saying they were “disturbed” by the incident.

The Town Board suggested reaching out to homeowners across the town next year to make next year’s process is smoother. Board member Jill Doherty said communication should start in February or March, when appointments could be set up to discuss the fencing.

She also suggested issuing the environmentalists town employee identification badges, so homeowners know they can be trusted.

Town Supervisor Scott Russell said the environmentalists will meet with the town after the summer season to discuss planning for next year.

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