There are no squirrels on Chappaquiddick. Well, that is until a week ago.

The first squirrel to be seen on the tiny island in many years was spotted on Thursday, Feb. 23, and word is spreading, along with concern.

Cuttyhunk has no squirrels. There are none on Noman’s Land and none on the Elizabeth Islands, according to Gus Ben David 2nd, a noted Vineyard naturalist and owner of World of Reptiles and Birds Park in Edgartown.

Mr. Ben David didn’t see the gray squirrel on Chappaquiddick, but he was with those who did; they were in a two-car caravan, driving back from the Dike Bridge and near Mytoi after an over-sand visit to Cape Pogue.

Tim Baird of Edgartown saw it. Toad Herring and his wife, Hannah, from Scotland Neck, N.C., saw it, along with Clay and Ada Sheilds, also of Scotland Neck.

Sheila Baird, Mr. Baird’s wife, and Mr. Ben David did not see the squirrel.

Seeing a squirrel ordinarily is not a notable event. That is unless you are on Chappaquiddick. “There are no squirrels on Chappaquiddick,” Mr. Ben David said.

Mr. Ben David was driving his truck at the time of the sighting. “Toad said he saw a squirrel,” Mr. Ben David said.

“I said, ‘Toad, are you sure? There are no squirrels on Chappaquiddick,’” Mr. Ben David said. “He said he saw it.”

“His wife, Hannah, joined in. She said she saw it too,” Mr. Ben David said.

When the two vehicles stopped to refill their tires at Mytoi, Mr. Ben David said he got out of his vehicle and went over to Mr. Baird, who was filling his tires with air.

Mr. Ben David said there was a moment of silence between the two men.

“Did you see that squirrel?” Mr. Ben David said he asked his longtime naturalist friend. “He said he did,” Mr. Ben David said.

Mr. Ben David, who often finds himself in the middle over the authentication of sightings of different creatures on the Island, said he has full confidence in the sighting by his friends.

Referring to another, far more unusual sighting reported on the Vineyard last year, Mr. Ben David said:

“I cannot say we have a definitive sighting of a coyote on the Vineyard. A definitive sighting depends on who saw it. But I can tell you there is at least one squirrel on Chappaquiddick.”

Word of the sighting traveled quickly among the winter residents of the small island that sits off the eastern end of Edgartown and can only be reached by taking a three-car ferry.

One of those residents is Edith (Edo) Potter of Pimpneymouse Farm, now 85, and the resident historian who published a memoir last year about growing up on Chappy. Mrs. Potter, who has a few memories of a squirrel or two on her island, learned about the recent sighting from a Chappy ferry captain four or five days ago.

“I can’t believe it,” Mrs. Potter said. “I am horrified.

“With all these wonderful years we have not had squirrels on Chappaquiddick. I hope there is only one,” she added.

“We have skunks. We have raccoons,” Mrs. Potter said, but she noted that her bird feeder on the farm has been squirrel free. The only concerns she has with her bird feeder are errant crows and guinea hens.

Mrs. Potter recalled one time about 10 years ago when a squirrel came over on a load of lumber from Cottle’s lumber yard.

Mr. Ben David said gray squirrels don’t like the marine environment. They prefer forests, especially oak forests, he said. And there was a time when much of the Vineyard was open land and lacking forest and woodland, and hence not a favorable place for squirrels. “They are arboreal rodents, related to rats and mice,” Mr. Ben David said. “They are basically dependent on woodlands, more closely lined with oak forests. Their life cycle is intertwined with the number of acorns.”

Be he also noted that Chappy, like the rest of the Vineyard, has experienced reforestation over the last 50 years.

Meanwhile, Skip Bettencourt of Chappaquiddick is looking for any information he can on the whereabouts of the squirrel. Mr. Bettencourt, who grew up on Chappy, said he has a trap and could help take care of the problem.

“I seem to remember way back, six years ago, a truck with wood came over [that had squirrels in it]. A few of us got together and got rid of them,” he said.

“We got chipmunks,” Mr. Bettencourt said. But of squirrels, he said: “They are a nuisance.”

Added Mr. Ben David, “That squirrel will now have a very precarious existence.”