The three men scramble across the steep hillside, clinging to clumps of coreopsis and bunch grass. The foaming sea crashes on the jagged black rocks more than a hundred feet below.
As they near their destination--a tiny cave carved from the stern cliff face--a proud, big-winged bird circles, swooping down and screaming her shrill warning cry: Caaaa caaaaa caaaaa!
The bird is a peregrine falcon.
The men, rangers and biologists from the Channel Islands National Park, are hiking to her nest. It is hatching season, and they hope to find some chicks.
After being driven to near extinction in the past four decades by the deadly pesticide DDT, peregrine falcons--which once soared above the Channel Islands in great numbers--have been returning to the islands' pocked volcanic cliffs.
First they were released into the wild by humans. Then some began migrating south from their strongholds farther north, such as Big Sur. In the past several years the falcons have begun--slowly--to reproduce on the islands.
Now there are at least 14 peregrine falcon pairs on the five islands that make up the national park: Santa Cruz, Anacapa, San Miguel, Santa Barbara and Santa Rosa.
Perched at the top of the local food chain, peregrine falcons are considered an indicator species--an index for the health of all the animals and plants beneath them.
The world's largest DDT deposit, about 100 tons, sprawls across 27 square miles of the ocean floor about two miles off the Palos Verdes Peninsula. Montrose Chemical Corp., which manufactured the pesticide at a plant near Torrance from 1947 to 1971, flushed waste into the county sewers.
Decades later that poison still lingers in the sediment on the ocean floor and works its way up the food chain.
But park Supt. Tim Setnicka, one of the three hikers, calls the falcons' homecoming a symbol of returning environmental health on the wild chunks of rock off the coast of Ventura and Santa Barbara counties.
On this day the men will see how many falcon chicks have survived, gather eggshell fragments to test for pesticide effects and tag chicks so they can monitor their travels and whether they reproduce in the wild.
Sweaty and streaked with dirt, the men reach the cave and peer into the shadows.
There sits a single terrified chick. Her shattered eggshell is scattered about.
She is soft, with white down like the inside of a pillow, but already she is armed with talons more than half an inch long. She is 23 days old and she is alone.
She will unsteadily take wing--or fledge--in about 20 days.
Park field biologist Brian Latta reaches in with his bare hands--gloves might hinder the delicate process--and grabs the chick. She screeches and scratches, drawing his blood.
Her startled eyes dart about as Latta deftly clips a silver tag onto her ankle.
"Looking at a young peregrine is like looking into the soul of the Channel Islands," Setnicka says. "If the birds of prey are coming back, it means the islands are less polluted."
"It's time to consider bringing the eagle back."
At the turn of the century, birds of prey made their homes in the cliffs and canyons up and down the craggy California coast. There were more than 300 peregrine falcon pairs in the state, biologists say.
Revered as the fastest flying bird, the peregrine is an aerial predator that can dive at speeds exceeding 150 mph. The peregrine's name derives from peregrinus, meaning wanderer.
Monogamous birds, they usually mate for life. The female is bigger, and built for battle, says Latta; the male smaller, and built for speed.
Ninety-nine percent of their diet is other birds. They dive through the air and kill prey with their talons.
"It is like someone riding by on a motorcycle with a switchblade and going for the jugular," Latta says.
Like the brown pelican and bald eagle--also once common in Southern California--the peregrine falcon suffered horrendously as the pesticide DDT caused their eggshells to become so thin they were crushed during incubation.
By 1955, peregrine falcons and bald eagles had disappeared from the islands. By 1970, there were bets that the brown pelican would become extinct on both the East and West coasts.
After a national furor, DDT was banned in 1972.
Although experts say pelican eggs are still thin, pelicans have recovered to the point that the stately seabird could be upgraded on the federal list from "endangered" to "threatened" as early as this summer.
Today, only a handful of peregrine falcons nest along the coast from Santa Barbara south to Mexico. Some of them now prefer the concrete canyons of cities to their traditional cliff eyries.
But the Channel Islands have become a stronghold of the peregrine falcon, Latta says.
During the 1980s, biologists worked with the park service to place and foster between three and seven young falcons each year on the islands. By the early 1990s, the birds were beginning to reproduce on their own.
"The Navy used to take us out in the '70s and '80s," says Brian Walton, coordinator for the Predatory Bird Research Group of UC Santa Cruz, which conducts its research with private funding. The organization has released peregrine falcons all over California. "I went out for years and years and we never even saw one."
But in the 1980s they started releases on San Miguel Island. A pair of peregrines bred, Walton says, and since then more have done so.
Walton's studies show that 69 wild young falcons have fledged from nests in the Channel Islands National Park since 1990.
Of the seven chicks that researchers were able to tag--often the cliff nests are inaccessible--six remained on the islands.
Walton says peregrine eggs laid on the Channel Islands are still only 80% to 85% as thick as they should be. And he says thinning of eggshells on the Channel Islands is still greater than in California as a whole.
Nevertheless, Walton says, the increasing population is significant.
"If you put them out there, even if they fail, they are dispersing in California," he says. "They are looking for places to nest. And if others nest there, the population will still increase, even if there are not a whole lot of chicks out there. It establishes a nucleus."
Looking into the cliff-side eyrie on west Anacapa, Latta estimates that the chick squawking in his hands is the sole survivor of two clutches of eggs laid by the mother.
But peregrine falcons have fared so well--despite continued problems with reproduction--that experts favor releasing bald eagles on the islands.
"It's such a perfect habitat," Walton says. "It's unique in terms of California. It's undisturbed, pristine, and virtual wilderness compared to most places that have heavy human impact."
Bald eagles have been successfully fostered on Santa Catalina Island and Big Sur. Techniques have been refined. The number of pairs on the Central Coast has gone from zero a decade ago to five to 10 pairs today.
Walton says that if the mainland bald eagle population gets large enough, birds may eventually migrate on their own to the wind-swept eyries of the park. But that could take decades, and eagle babies are ready for release now.
"They didn't evolve in a way that encourages them to go nest in the wild blue yonder," Walton says. "Instinct drives them to nest where other birds already are nesting."
And that is where humans can help.
Robert Mesta, a biologist for the U.S. Fish and Wildlife Service and a predatory bird expert, agrees.
"If peregrines can hatch on the islands successfully and fledge, there is no reason the bald eagles couldn't," he says. "It's an opportunity to place eagles where they originally nested.
Latta gathers up feathers, shells and packs them into sandwich bags, while the chick squawks and flaps her wings helplessly in the corner of the cave.
As the men begin their trek back across the hillside, carefully stepping over sea gull nests and just-hatched chicks, the female peregrine falcon screeches above.
She is following them down to the boat, escorting them off the island.