Patrolman Ed Cunningham noticed nothing unusual as he cruised the empty streets of Capitola, California, in the early morning hours of August 18, 1961—least of all the thick summertime fog that enveloped the oceanside resort south of San Francisco. All remained quiet until 2:30 a.m., when a deluge of charcoal-colored birds erupted from the gray shroud, pelting his patrol car and shattering its spotlight.
Forget cats and dogs—the birds rained down with such force that Cunningham feared leaving his car to investigate. “They fell so fast they could have knocked me down and out,” he said.
Rolling off Monterey Bay’s northern shore, a feathered tsunami crashed across the coastal town. Waves of disoriented birds slammed into houses, collided with lampposts and struck power lines. Roused by the relentless percussion on windows and rooftops, startled residents ventured into the murk with their flashlights, only to be swarmed by swooping birds drawn to the beams.
If the avian maelstrom sounds like a scene straight out of a Hollywood horror movie, it’s for good reason. The real-life event played a starring role in the production of Alfred Hitchcock’s 1963 film The Birds.
Birds Overrun Capitola
Before dawn that morning, 21-year-old George Dymesich left his apartment for his summer job on Capitola Wharf. As he peered into the thick fog, he discovered birds carpeting the roads. “You couldn’t see more than about 10 or 15 feet, and hundreds of these black birds were laying all over the streets,” he recalls.
That morning was no day at the beach for 10-year-old Erin Coolman. She had heard strange thuds on the roof of her family’s fog-bound beach house during the night. “When we got up in the morning, we couldn’t believe our eyes,” she remembers. “The alleys were littered with dead birds two or three deep. There were hundreds of them everywhere.”
The erratic birds staggered through Capitola like web-footed revelers stumbling home after last call. They bit residents and regurgitated half-digested fish onto lawns and rooftops, producing an overpowering stench that repulsed locals and delighted prowling cats. One panicked resident thought the town was under attack by “bird men,” while the manager of the Venetian Court Motel believed it to be “germ warfare” if not “the end of the world.”
The sooty shearwaters who invaded Capitola were familiar summertime visitors. Each year, upwards of 1 million of the gull-like birds flocked to Monterey Bay from breeding grounds as far-flung as New Zealand to feast on squid and anchovies.Unlike the tourists who filled Capitola’s colorful cottages, however, the seabirds typically stayed offshore.
Wearing gloves to protect their hands against the pecking birds, volunteers mounted a rescue operation to return the sooty shearwaters to the Pacific Ocean where they could more easily take flight. “We were tossing them out in the surf, but they were coming back in,” Dymesich remembers. “So, we started taking them all the way out to the wharf where there was a ladder to a floating dock, and we set them free there.”
By mid-morning, the winged invasion had abated, leaving behind a mess of feathers, feces and carcasses littering the town and four miles of beaches. “We went around the neighborhood filling up garbage cans with dead birds,” Coolman says. “The whole village came out in force and cleaned them up.”
Hitchcock Seeks News of the Attack
As Capitola recovered that morning, news of the bizarre episode reached Alfred Hitchcock in Hollywood. The legendary film director just so happened to be developing a treatment for The Birds, a thriller based on Daphne du Maurier’s 1952 novella of the same name, after purchasing the rights a year earlier.
For Hitchcock, the avian attack on Capitola hit home in more ways than one. Since 1940, the London-born director had owned a 200-acre estate in nearby Scotts Valley on the slopes of the Santa Cruz Mountains. He frequented Capitola’s restaurants and walked his dogs on nearby beaches.
Familiar with the local Santa Cruz Sentinel, Hitchcock called to request a copy of that day’s newspaper. He rang again the following day to say he was using the newspaper “as research material for his latest thriller.” When asked if he was behind the incident, given his latest project, the master of suspense replied in his signature purr: “Merely a coincidence.”
Hitchcock Produces ‘The Birds’
Hitchcock retained key elements of du Maurier’s story but made extensive changes, including expanding the cast of characters and relocating the setting from an English coastal farm to a seaside village in northern California—though not Capitola. The Birds takes place 140 miles north in Bodega Bay, which had its own real-life bird trouble when ravens fatally attacked dozens of ewes and lambs.
Described as the “grand-daddy of all animal-attack thrillers,” The Birds debuted in March 1963. “It could be the most terrifying motion picture I have ever made,” Hitchcock said.The scenes of crazed birds swooping down chimneys, rampaging through attics and pelting phone booths stirred memories of that August day for Dymesich. “Everybody who was down there that morning probably flashed back on it,” he says.
The screenplay references the 1961 aerial assault but shifts the location to a neighboring locale. “Something like this happened in Santa Cruz last year. The town was covered with seagulls,” recalls one character. “They made some mess, too, smashing into houses and everything.”
That allusion raised eyebrows in Capitola. “In reality, he should say Capitola or Pleasure Point because that’s really where it occurred,” says Deborah Osterberg, curator of the Capitola Historical Museum. “Hitchcock was very well aware of Capitola, so it’s strange to me that he mentioned Santa Cruz in the movie.”
Audiences hoping for a tidy ending left the theater dissatisfied as Hitchcock’s movie offered no explanation for the birds’ unusual aggression. “We decided that it would be science fiction if we explained why the birds were attacking,” said screenwriter Evan Hunter. “It would have greater meaning if we never knew.”
For decades, the cause of the 1961 Capitola bird invasion also remained a mystery—until science eventually cracked the case.
Scientists Identify Bird Invasion Culprit
In the invasion’s immediate aftermath, numerous explanations emerged: The birds were dizzy from overeating or confused by heavy artillery fire at nearby Fort Ord. “One of the educated guesses was that the birds lost their way in an ocean fog, which makes no sense because we always get fog here in the summer,” Osterberg said.
Fast forward to 1991 when more than 100 brown pelicans and cormorants died on the north side of Monterey Bay. Investigators subsequently discovered that the birds had eaten anchovies laden with domoic acid, a naturally occurring poison made by a marine phytoplankton called Pseudo-nitzschia.Domoic acid—which becomes more concentrated as it moves up the food chain—can cause disorientation, seizures and death.
A 1995 study led by UC Santa Cruz oceanographer David Garrison theorized that toxic microalgae caused the 1961 event, but proof was lacking until a team of researchers published a 2012 study in the journal Nature Geoscience. By analyzing gut contents of archival zooplankton collected from Monterey Bay in July and August 1961, the scientists discovered at least 79 percent of the plankton were infected with the toxic Pseudo-nitzschia. The deadly poison moved through the food chain, from fish to birds, and eventually made its mark on one of cinema’s most iconic thrillers.
