An emaciated juvenile bald eagle is getting special care and eating well on the Island after being captured on Chappaquiddick on Saturday, August 16.

Gus Ben David, who runs World of Reptiles and Bird Park in Edgartown, has the bird in a cage. He is feeding the animal road-kill rabbits and laboratory mice, and so far he thinks he can save her. The prognosis is good for the eagle’s eventual release back in the wild, although recovery may take months. Mr. Ben David said he wonders how the two-year-old bird got in trouble.

The bird was first spotted the morning of Friday, August 15, by Victor Colantonio, who lives near the Cape Pogue lighthouse. It all began on Thursday when a large flock of thousands of swallows arrived on the outer area of Chappaquiddick. It got Mr. Colantonio’s attention. On Friday morning it was his interest in those little birds, that he took his wife and friends out for a ride that they discovered the troubled bald eagle.

“We saw just above the high tide line a bald eagle, sitting on the wrack line. We walked as close as four to five feet. We knew something was wrong. We’ve viewed eagles in Alaska and this was not right,” Mr. Colantonio said. He, his wife Dawn, and guests David and Mary Levine from Andover, agreed a call needed to be made. Mr. Colantonio said they called the sighting in to The Trustees of Reservations, who oversee the Cape Pogue Wildlife Reservation, a 516-acre area that surrounds most of Cape Pogue and includes the Cape Pogue lighthouse.

“I phoned it in as an injured bird,” Mr. Colantonio said.

Richard (Dick) Jennings a tour guide ranger and Elizabeth (Liz) Baldwin, a shore bird biologist with the Trustees investigated.

They contacted Mr. Ben David later in the day.

“Dick and Liz reported to me that the eagle was acting strange and was in a weakened condition,” Mr. Ben David said. The description of the bird’s behavior suggested something was truly wrong. The animal could barely fly and when it was coming in for a landing it crashed like an inexperienced pilot, Mr. Ben David said.

On Saturday morning, Mr. Ben David said he was taken on a special trip by the Trustees staff out to the site. “We immediately located the eagle where it had spent the previous night. I sized up the whole situation. I definitely confirmed that the bird was in a weak state with problems. That is when I made the decision we will take this bird out of the wild.”

Using bunker he was given by Cooper A. Gilkes 3rd of Edgartown, Mr. Ben David was able to lure the bird to a place where it could be caught safely. He said he tied a piece of string to the menhaden and pulled it across the sand out in front of the bird. The bird followed the fish and went for it. At that moment, Mr. Ben David was able to capture the bird.

Bald eagles are a federally and state protected bird and once suffered serious decline. Through years of effort, their numbers in New England are increasing. The Vineyard is visited every summer by juvenile eagles; there is plenty to eat, Mr. Ben David said. In years past, Mr. Ben David said he can recall when there were at least six juvenile birds feeding on the Island.

“We get them every year, they are getting more and more common,” he said. “The immatures, once they are fledged, will leave the nest and become erratic wanderers. They go up and down the eastern seaboard and quite a few go inland. They do this until they reach the breeding age, which is four to five years old. At that time the birds will have a tendency to go back to their native area, usually the same state, in most cases. They go there to breed.”

Mr. Colantonio said later on Saturday, he and his friends saw another young bald eagle flying over the Trustees’ shack down at the Dike Bridge. “That bird was extremely healthy and magnificent,” Mr. Colantonio said.

Mr. Ben David owns two eagles and is considered a top state authority on birds of prey. He has an 18-year-old female bald eagle named Wrangler and a 28-year-old female golden eagle called Chaneli.

It is customary that when an eagle or any valued bird gets into trouble someone like Mr. Ben David is called in. He said based on his watching the eagle, he can’t see any physical problem. If the eagle had a broken wing or some physical trauma, it would be sent to Tufts Center for Conservation Medicine at Tufts University. Instead, in this case Mr. Ben David said he is consulting with his experts to make sure that all that is needed to be done gets done.

“I will evaluate the bird as we go. I will communicate that information to the state and federal government,” Mr. Ben David said. “Even though the bald eagle is off the endangered species list, they are still a threatened species and protected totally by law.”

He said his purpose now is to get the bird back up to its proper body weight and understand why she got in such bad shape.

Last Friday, in Susan Whiting’s bird column in the Gazette, she wrote: “Frequently young birds don’t learn how to hunt right away and weaken. It was presumed that might be the case.”

Mr. Ben David said he believes the animal is two years old but he doesn’t know what brought probably a healthy bird down this troubled state. “If everything seems okay, we will release her,” he said. The bird now resides temporarily in the same cage as Wrangler. The bird is not on public display.

“If I detect some behavior problems, some inequities, then she could become an education bird or an exhibition bird. That is down the line,” Mr. Ben David said. “Within two months, I think I will know,” he said.