BANGOR — On Sunday, area bird-watchers were stunned when over a seven-hour period, one adult bald eagle was discovered standing, apparently ill, on a sidewalk, and another, presumably its mate, flew into electric wires and died.

On Monday, a crew methodically assessed the situation, sent a climber up a large white pine tree to the eagle nest some 90 feet above the ground, and rescued two orphaned eaglets, which were immediately fed electrolytes and taken to Avian Haven, a bird rehabilitation facility, in Freedom.

The two eaglets will be reunited with their mother at Avian Haven.

Maine Game Warden Jim Fahey responded to the Sunday morning call about a disoriented adult female eagle on Harlow Street in Bangor, near Kenduskeag Stream. The eagle was captured and taken to Avian Haven.

“She’s doing much better this morning,” Diane Winn, co-owner of Avian Haven said Monday, shortly before the rescue mission began. “Shortly after she came in last night, she basically lay down on a foam bed and passed out. She was flat down, not moving at all, eyes closed.”

The eagle was fed activated charcoal to treat suspected toxin exposure and seemed to have recovered substantially by Monday morning.

“This morning, I came down around 6 [a.m.], and her eyes were open, and she was half upright,” Winn said. “As of now, she’s standing, she’s looking around, and she’s very bright and alert.”

Winn said the eagle did test positive for higher-than-normal levels of lead in her blood.

“What we were seeing [in the bird’s behavior] was [indicative of something] much more recent and acute [than lead poisoning],” Winn said. “What the toxin was, I have no idea.”

At about 7:30 p.m. Sunday, Fahey said he received word of another eagle in trouble, in the same Kenduskeag Avenue neighborhood as the first.

“[A witness named] Ryan Robbins called in to report that he and this other fellow actually witnessed the second mature bald eagle,” Fahey said. “It flew somewhat erratically and failed to secure a perch on a tree limb. It basically tumbled into a set of power lines and got electrocuted.”

That eagle, a male that was presumed to be part of a nesting pair that includes the ill female eagle, was taken to a Maine Department of Inland Fisheries and Wildlife storage facility. A decision on whether to test the eagle for possible toxins has not yet been made, according to DIF&W bird group leader Brad Allen.

On Monday morning, Allen was at the nest site on Kenduskeag Avenue, just up the hill from Harlow Street. Joining him were Fahey, Avian Haven co-owner Marc Payne and Brent Bibles, an assistant professor of wildlife biology and tree-climbing expert from Unity College who has done raptor research for years.

Bibles, hooked into a climbing harness, took more than 30 minutes to scale the massive white pine and reported his findings to the crew on the ground.

“We’ve got two,” he shouted when he reached the nest.

Bibles placed the two eaglets in a leather bag, which he then lowered to Allen and Payne.

The biologist and rehabilitator rushed to Payne’s nearby car, where Payne squirted a solution of electrolytes into the mouths of both fuzzy eaglets.

Allen estimated the age of the baby birds at about six weeks.

Shortly after that, the birds were taken to Avian Haven, where they’d be evaluated and nursed back to health. Before too long, Payne said, they’d be spending some time in close proximity to their mother in order to re-establish that bond.

“We’ll definitely brainstorm with Charlie [Todd, DIF&W eagle specialist], Brad and everybody about what’s best for the birds,” Payne said. “We definitely want to rehydrate them, warm them up.”

Wildlife photographer Sharon Fiedler of Bangor was at the site Monday, taking photographs of the nest that she has spent close attention to over the past three years.

In fact, Fiedler watched the pair of eagles try to build their first nest — one she called “haphazard” — at a failed site nearby. Fiedler was saddened about the two adults but was one of the most enthusiastic observers when the two eaglets were lowered to the ground.

“I caught [the adults] mating in February [of 2013] over at Lovers Leap,” she said, referring to a cliff not far away on Kenduskeag Stream.

Using her photographic skills, she was able to zoom in on the female eagle’s legs and determine the identification number engraved on the bands she had been fitted with.

After some research, Fiedler learned that the female hatched in 2010.

“It was a born in Winslow, and it left the alewife run to come up here and find a hot date,” she said.

Allen said the nesting pair have had troubles in the past, and the nest was well known to biologists.

In July 2013, one eaglet fell from the nest and walked downtown, where Allen captured it in a parking lot next to Kenduskeag Stream. The bird also ended up at Avian Haven for rehabilitation before it was released in September.

“We couldn’t figure out a way to get it back into the nest, and we weren’t sure if the parents would tend to it on the ground here because of the urban setting, so we chose to raise it in captivity and let it go,” Allen said.