In June, a pair of golden eagle chicks were discovered in a nest in a remote area of the western Santa Monica Mountains. The last time a nest was confirmed in Santa Monica Mountains National Recreation Area was in the late 1980s near Lobo Canyon, in the central portion of the mountain range.
The chicks, a 12-week-old male and a female, were located when a consultant conducting bird surveys on private property identified the golden eagle pair and notified park biologists. NPS biologists working with biologists from the U.S. Geological Survey and Bloom Biological Inc. confirmed the nest location and activity and banded the young.
“Each chick received two bands—one colored and one numbered. The bands are part of the USGS Bird Banding Laboratory to help scientists monitor the status, trends and ecology of resident and migratory bird populations. Biologists also took blood samples from the chicks for genetic testing.
Loss of habitat for nesting and hunting has reduced their range in much of the state, according to Katy Delaney, an ecologist with Santa Monica Mountains Recreation Area, a unit of the National Park Service.
Golden eagles are the largest of the 11 raptor species—birds that hunt and feed on other animals—that breed in the Santa Monica Mountains. Dark-colored red-tailed hawks are sometimes mistaken for golden eagles by inexperienced observers, but the eagles are much larger that the hawks—an adult female golden eagle can have a wingspan greater than six feet wide, compared to the red-tailed hawk, with a span of slightly more than four feet.
Golden eagles are a fully protected species, thanks to the Bald and Golden Eagle Protection Act of 1972, and the Migratory Bird Treaty Act, but the birds faces many challenges.
“Humans are the greatest threat to golden eagles,” Delaney said. “In the past, they were trapped and shot throughout their range and today, they are vulnerable to habitat loss. Like their mammalian carnivore counterparts, they can die from eating poisoned prey as well as from lead poisoning, electrocution on power lines, and collisions with wind turbines.”
There have been a number of golden eagle sightings in the area over the years, but the presence of a successfully breeding pair and their offspring was hailed as an auspicious sign.
“We haven’t seen them in so many years, though they could have been around and staying away from people.” Delaney said. “We just went through a huge fire and drought, and we’re also not going to see a decrease in urban development. Nonetheless, this is a good thing for our mountains. We not only have mountain lions here, but we have golden eagles, too.”
News of the nest was not released until the young birds had successfully fledged. For the next several months, the chicks will continue to rely on their parents, while they learn to successfully hunt on their own. The biologists monitoring the next predict that the young birds will be ready to disperse on their own by late fall. “
After gaining independence, young eagles generally disperse out of their parents’ breeding territory, travelling between 20 to 1,200 miles away, but usually return when they are four to five years of age to establish their own nesting territory,” National Park Service Senior Writer Ana Cholo reported.
“These birds of prey typically feed on rabbits and squirrels, but also take a diverse array of prey species from small birds and snakes up to mule deer fawns and coyote pups,” “Carrion is also an important component of their diet. In the case of this family, western gulls was the prey item of choice at the time of banding. There were seven gull wings found in the nest, located in a large cave.”
Cholo explained that golden eagles frequently form strong pair bonds and exhibit high mate and territory fidelity, meaning they will likely stay with the same partner and return to the same nest each breeding season. Some Southern California adults remain on or close to their nest territory throughout the year while others move on.
Biologists believe the population may be declining in the United States, especially in California.
Historically, golden eagles nested throughout the Santa Monica Mountains from the Gorge in Malibu Creek State Park to Boney Mountain in Point Mugu State Park. Cholo writes that, according to local Chumash Indians, golden eagles had a deep historical connection to Boney Mountain but the last known confirmed nesting there occurred in the early 1980s.
A nesting pair was observed north of the 101 Freeway in the Simi HIlls at Cheeseboro Canyon in the 1990s but nesting has not been detected in the Santa Monica Mountains since the 1980s. A survey of the mountains in the 2000s did not yield any active golden eagle nests.
Observers hope the presence of this newly discovered family of golden eagles may mark the species return to the area.
Santa Monica Mountains National Recreation Area (SMMNRA) is the largest urban national park in the country, encompassing more than 150,000 acres of mountains and coastline in Ventura and Los Angeles counties. A unit of the National Park Service, it comprises a seamless network of local, state and federal parks interwoven with private lands and communities. As one of only five Mediterranean ecosystems in the world, SMMNRA preserves the rich biological diversity of more than 450 animal species and 26 distinct plant communities. For more information, visit www.nps.gov/samo.