- [Narrator] In the Santa Cruz Sentinel,
August the 18th, 1961, there is an account
of thousands of birds raining down from the sky at 3:00 AM,
crushing into homes and cars in Capitola
and Pleasure Point, California, just off Monterey Bay.
"Eight persons were reported bitten."
This is the bird, ardenna grisea, the sooty shearwater.
Also noted, the word of the bird invasion spread
fast throughout the state.
And a phone call came to the Sentinel
from mystery thriller producer Alfred Hitchcock
from Hollywood.
- [Producer] Roll five, Alfred Hitchcock.
- [Narrator] He requested a copy of that day's paper.
He was, after all, adapting a particular
1952 Daphne du Maurier story into a screenplay
on the subject of killer birds.
Less than two years later, Hitchcock's The Birds premiered.
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There's this too, prevailing theories at the time supposed
the sooty shearwaters got lost in the fog,
that the flock of thousands was confused.
That theory made it into Hitchcock's film.
- Hey, something like this happened in Santa Cruz last year.
The town was just covered with seagulls.
- Will you please finish your drink.
- That's right, sir, I recall it.
A large flock of seagulls got lost in the fog
and headed into the town where all the lights were.
- And they made some mess too,
smashing into buildings and everything.
- [Narrator] You might be asking yourself
what made them do this?
Because just look at these sooty shearwaters
navigate the fog.
If flocking birds were easily confused in low visibility,
shearwater invasions would be as common as passing rain.
This all makes me think to understand what happened,
first, you need to know how a flock of birds,
like thousands of shearwaters, fly and move together.
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Ancient Romans said the gods guided flocking birds.
At the turn of the 20th century,
learned scientists considered
natural telepathy or a group soul.
So, magic.
After all, just look at these starlings flying.
Unlike a flock of geese, where there's an obvious leader,
like this captain goose right here,
any bird in a flock cluster can move
in any direction and the others will follow suit.
That's because flocking birds aren't just aware
of their immediate neighbor.
Point of fact, they're focusing on the small group
of birds around them, up to six or seven, like so.
Sort of like a rippling effect of consciousness.
In 1986, programmer Craig Reynolds made this,
a three-dimensional flocking model.
He called his flying creatures boids.
Three simple steering behaviors guide them.
Input one: coherence.
Fly close to the other boids.
Input two: separation.
Don't run into your flock mates.
Input three: alignment.
Match the speed and direction of the boids around you.
This math basically plays out in nature
each time a flock takes flight.
Kind of fantastic, right?
Now consider if a fourth input was introduced
to the flock of boids, a piece of malware
instead of a computational rule.
That's what happened to the sooty shearwaters.
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Edna Masini, proprietor of the Venetian Court Motel
on the beach at Capitola in 1961,
wrote about the day the birds came.
- [Edna] Struggling to the door,
I was awed at the sight of hundreds of birds,
all with the cry of a baby.
They were heavy with sardines, unable to fly,
and lost in the dense fog,
as they came in from the sea attracted by our lights.
They slammed against the building,
regurgitating fish blood, and knocking themselves out.
Our manager phoned me, asked what to do.
She knew it was the end of the world.
Panic set in, sure it was German warfare.
- [Narrator] Heavy with sardines
and regurgitating fish blood are two curious observations.
The sooty shearwaters seemed more sick than lost.
30 years past until, in the Santa Cruz Sentinel,
September 15th, 1991, there is another account
of confused birds in Monterey Bay.
The bird, pelecanus occidentalis, the brown pelican,
also some cormorants.
There was no hale of birds, like the incident in '61,
they simply washed ashore.
But the pelicans exhibited similar symptoms.
This time scientists determined the cause,
domoic acid poisoning.
Domoic acid is a neurotoxin that can be produced
by several species of pseudo-nitzschia, a micro algae
that flourishes in nutrient-rich warm water and low wind.
What happened is domoic acid infiltrated the food chain,
making its way into plankton, then anchovies,
then the Brown pelicans.
And when the neurotoxin passes
through the blood-brain barrier in birds and mammals,
it can cause confusion, disorientation,
seizures, coma, even death.
So when domoic acid incidents became more common
in the 2000s, more Brown pelicans, more cormorants,
and even sea lions, dots, of course, we're connected.
Dr. Sibel Bargu Ates, a biological oceanographer
and professor at Louisiana State University,
along with a team of researchers thought
maybe the dots went as far back as 1961.
In 2011, they analyzed the gut contents
of archival zooplankton specimens,
sampled from the same location and time period
as the sooty shearwater frenzy.
And, they were full of pseudo-nitzschia fragments,
the micro algae that produces the domoic acid toxin,
meaning the food chain was more than likely contaminated.
So the sooty shearwaters didn't get lost in the fog.
They were poisoned.
The fact they flocked together in the thousands
and all fed on krill or sardines tainted
by the toxic micro-algae is what made
that fateful night feel like the end of the world,
because the birds collectively lost
their minds at the same time.
One question, naturally, remains.
Why did Hitchcock's birds attack?
- What were the crows after at the school?
- What do you think they would after Miss?
- Daniels.
I think they were after the children.
- For what purpose?
- To kill them.
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