Friends in high places: Peregrine falcons soar above us

Not long ago, Berkeleyside reader Patrick Hickey kindly sent in a photo of a beautiful bird of prey, perched on a tall building near his home in downtown Berkeley. I had my own suspicions (and sense of elation) over what kind of bird it might be. Then Rusty Scalf, teacher and trip leader for the Golden Gate Audubon Society, confirmed it: the bird was a peregrine falcon — the fastest animal on Earth. In California, not long ago, it was also one of the most endangered.

“Many of us were looking at the extinction of the peregrine in the 1970s,” said Glenn R. Stewart, director of the Santa Cruz Predatory Bird Research Group (SCPBRG) . “It really looked like they were going to be gone forever.”

At that time, Stewart and other scientists could find only two pairs of peregrine falcons in California. In the eastern part of our country, peregrines were totally gone.

The pesticide DDT — widely used in the 1940s, 50s, and 60s— accumulated in the fatty tissues of peregrine falcons (and also, bald eagles), causing these birds to lay thin-shelled eggs that broke in the nest during incubation.

With the banning of DDT in 1972, and decades of impassioned work by Stewart and the SCPBRG, peregrine falcons have undergone a near-miraculous recovery.

Today, an estimated 250 to 300 peregrine pairs are living and nesting in California, a number  that Stewart believes approximates original pre-DDT populations. Forty-five or 50 of these pairs live in the greater Bay Area, from Napa and Marin Counties south to Mount Hamilton.

“The crux of it, really, was that the peregrine recovery work wasn’t a government project. It wasn’t a big corporate effort with a lot of money behind it. It was just a very few people with a powerful idea, who mobilized a bunch of other people,” Stewart says.

By the 1990s, the SCPBRG had successfully released 1,000 peregrines to the wild—plus hundreds more in the years that followed.

Recovery programs included captive breeding of peregrine falcons, the safe incubation of their thin-shelled eggs in the laboratory (replacing them, temporarily in the nest, with synthetic eggs that the parents treated like real eggs), and even the fostering of a few peregrine eggs in the nests of wild prairie falcons (which were less affected by DDT).

“The interesting part of the peregrine’s tale is their adaptability to the urban environment,” says Shirley Doell.

Doell is a peregrine volunteer — a “citizen scientist”— who ventures out at dawn nearly every morning in spring, plus some evenings, to monitor pairs of peregrines on skyscrapers, high-towered bridges, and tall industrial cranes in the East Bay. She and other falcon watchers share their observations, particularly about nesting, with Stewart, enabling research to continue.

“Most endangered species can only live in a particular niche in a particular kind of habitat,” Doell says. “But the peregrines don’t seem to mind the bustle and noise of the city, if there are tall structures and birds around for them to catch.”

In other words, she says: “They make their living out of thin air.”

In cities like Berkeley, Oakland, and San Francisco, peregrines hunt pigeons for about 90% of their diet. Worldwide, they prey on roughly 1,500 to 2,000 different species of bird, which is about one-fifth of the world’s known bird species.

“Peregrines are anchored in the desire to get food,” Stewart says. “And living in a place like downtown San Francisco, where there’s an abundance of pigeons… it’s like living on a remote island in British Colombia with an abundance of sea birds nesting. Only here, the cliffs happen to be buildings, or bridges. The food happens to be nonnative pigeons.”

In fact, Stewart thinks that Berkeleyans will get to view more peregrines in the future. Once, he says, he stood on the hill near Grizzly Peak, and from that high vantage, he could make out eight separate peregrine territories. That, to him, was a wonderful thing.

“For people to live with peregrines… to see them fly for the first time… They think about nature and conservation of nature. That’s the advantage. That’s the benefit we get from this,” he said.

So true, I thought, as my mind pictured the times I’d seen peregrines, chasing a bird above Cedar Street, swooping between Oakland skyscrapers, gliding eye-to-eye over the Bay Bridge.

They felt like fast friends.

Springtime for peregrines

By this time of year, peregrine falcons have already paired up. The “early birds” have laid their eggs and are high in their nests, incubating them. Others may wait several weeks to start their families. Around Memorial Day, “the kids,” as Doell fondly refers to them, will begin learning to fly.

Since their recovery, peregrine falcons have nested on most, if not all, of the major Bay Area bridges. Earlier this month, Doell watched as one of the more unusual nest sites — located on a counterweight of a drawbridge in Rio Vista—  went up and down with bridge operations. Eggs went along for the ride.

Learn your falcon-watching lingo:

peregrine : wandering, traveling, wayfaring. (Many peregrine falcons in the Bay Area are year-round residents. Others migrate here from colder areas, making peregrine sightings more numerous in winter. So-called “deep peregrines” may migrate 15,500 miles in one year.)

falcon : female falcon.

tiercel (pronounced “TEER-sull”): male falcon.

malar stripe (or sometimes called, “moustache”): the black stripe that extends down from a falcon’s eyes, across the “malar,” or side of the head.

scrape: a falcon’s nest site. (Peregrine falcons do not build nests of their own; instead they reuse the nests of other large birds, like ravens, or simply do “remodeling” by “scraping” out a depression in a gravelly surface.)

eyrie or aerie (pronounced “EYE-ree”): nest site of a falcon or other bird of prey, located in a cliff or other high, inaccessible place.

eyas (pronounced “EYE-az”): nestling falcon or other bird of prey.

stoop/stooping: to descend into a aerial hunting dive. (Peregrine falcons can stoop at over 200 miles per hour from thousands of feet in the sky. To Stewart, this is the stuff of “superheroes.”)

tagging: to hit a bird in midair. During a hunt we witnessed, the female “Pele” tagged a little bird; “Phoenix,” her mate, caught it as it fell. Then, he gave it back to her.)

loafing: to rest while perching. (A peregrine may loaf on a high ledge for hours, particularly, it seems, when a photographer wants to take a photo of it in flight.)

For more about peregrines:

• Check out the Santa Cruz Predatory Bird Research Group (SCPBRG)
• Watch the live peregrine webcam: San Francisco
• Watch the live peregrine webcam: San Jose
• Read about “Island Girl,” an intrepid “deep peregrine” that migrates from the Canadian tundra to the Chilean coast. A small, solar-powered radio transmitter on the bird’s back helps scientists track her long-distance journey, including a few apparent rest stops on oil rigs and ships in the Gulf of Mexico. (Provided by The Southern Cross Peregrine Project).
• Read Glenn Stewart’s inspiring memoir about working with raptors, Eye to Eye with Eagles, Hawks, and Falcons

Special thanks to Patrick Hickey, Shirley Doell, Glenn Stewart and the SCPBRG, Rusty Scalf (Golden Gate Audubon Society), Lisa Owens-Viani (RATS: Raptors Are the Solution), and John Greenleigh (Flipside Studios).

Elaine Miller Bond is the author/illustrator of “Affimals: Affirmations + Animals and Dream Affimals” — uplifting books of environmental education. She is also the photographer for the upcoming book, “The Utah Prairie Dog,” from the University of Utah Press.

Related:
Counting crows: Why are there so many in Berkeley? (03.28.14)
Darlings not Draculas: The bats that live in Berkeley (12.23.13)
In a Berkeley park a bluebird displays unusual behavior (08.05.13)
Lynxes of the bird world: Cooper’s hawks nest in Berkeley (04.18.13)
The mystery and thrill: Shorebirds enjoy winter in Berkeley (03.21.13)
Sitting on the dock of the bay: Birds throng Berkeley pier 02.28.13)
Rare bluebird sightings bring happiness in a Berkeley park (08.07.12)
In Tilden Park’s Jewel Lake: Spotting a rare river otter (04.05.12)
Up close with Berkeley’s wildlife at Tilden Regional Park (03.06.12)

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