ANGELES NATIONAL FOREST >> From its large nest atop an aged tree on the edge of San Gabriel Reservoir, the juvenile bald eagle squirmed, letting out a warning cry.

The message scared away the menacing turkey vulture. But instead of a fight call, perhaps it was a lament intended for absent parents seen two days prior by local bird-watchers guarding the eagle’s nest but nowhere in sight Tuesday.

• Video: A nesting, young bald eagle was found in the Angeles National Forest north of Azusa

Either way, the fuzzy-feathered fledgling is part of a nesting family of bald eagles, a rare sight for Los Angeles County, experts say.

“We have heard of some (bald eagles) in the San Gabriel Mountains National Monument but for me, this is the first time I’ve heard about a nesting pair,” said Travis Abeyta, Southern California chapter manager for Audubon California.

Abeyta positively identified the bird as a bald eagle chick, about 10-12 weeks old, using photographs provided by this news group.

Hikers and amateur birders Joann and Dennis Sanderson of Azusa saw the juvenile bald eagle, covered in brownish feathers and with a sharp, curved beak but lacking the distinctive white head, peeping out of the nest Saturday morning. On Sunday evening, the couple returned and saw an adult bald eagle with the white-feathered head. The same adult pair were featured in a photo Dennis Sanderson took in May 2015, shown nesting in the exact same tree, located a few miles north of Azusa in the San Gabriel Mountains.

• Photos: Bald eagles nest near San Gabriel Dam

The large nest, built high in an old, columnar tree, near a body of water good for fishing yet far away from people, is indicative of bald eagle-nesting behavior, Abeyta said.

Mostly, bald eagles in California thrive in the Klamath Basin and in the upper Pacific Northwest, he said. But the species, the beloved national bird of the United States, has been spotted in more unusual places of late, including Irvine Lake in Orange County and Lake Cachuma in Santa Barbara County, he said.

Bald eagles have been seen wintering in Big Bear, near Lake Perris, Lake Hemet and the San Jacinto Mountains in Riverside County since 1986. Mid-winter counts average about four adult bald eagles a year in Big Bear, according to the Riverside Press-Enterprise.

Kimball Garrett, the ornithology collections manager for the Los Angeles County Natural History Museum and author of “Birds of the Los Angeles Region,” said finding a nesting bald eagle in this area is a rare thing. He also positively identified the bald eagle from pictures provided to him.

• Video: An adult bald eagle joins the juvenile in its nest

“I’m not aware of any nesting of this species in L.A. County in several decades,” he said.

The California Department of Fish and Wildlife reports a 1.2 percent increase in bald eagles wintering in California from 1986-2005. More than half are spotted in Northern California.

It’s not clear how the drought, particularly felt hard in Southern California, has affected the rebounding bald eagle population. One theory says more pairs may come to warmer weather lakes and reservoirs where ducks and fish — sources of food — are exposed by low water levels.

The resident bald eagles may be using the San Gabriel Reservoir as a food source. It contains non-native fish such as bass and carp, explained Ann Berkley, wildlife biologist with the U.S. Forest Service.

Whatever the weather or location, seeing a bald eagle usually invokes an emotional reaction from humans.

“I think it is so cool it is so close to the second-largest city in the United States,” said Joann Sanderson, peering through her binoculars at the nesting bird.

A bicyclist pedaling up Highway 39 stopped, viewed the young bald eagle in the nest through a camera lens and smiled.

“It is pretty rare to see these babies here,” said Jose Lopez of Hacienda Heights.

Most likely, the immature chick will leave the nest shortly to fish for salmon in Northern California, Abeyta said. But because bald eagles mate for life, the two adult eagles may stick around, he said. It’s possible their offspring may return to join the family next year.

Berkley said she was expecting the adult pair to leave the area last year but they ended up staying, very much like humans who visit Southern California for the first time.

People have their own stories of seeing a bald eagle, a magnificent raptor with a wingspan of between 6 feet and 7.5 feet, one of the largest in North America. This bird is atop the food chain, eating fish and occasionally even a deer, Abeyta said.

“For me, when you see a bald eagle, it is the power and beauty and significance that bird brings. It brings home to me we are all in this together,” Abeyta said.