♪ (narrator) Peregrine falcons are the fastest animals in the world... [angry chirping] in more ways than one.

Making and raising chicks takes a lot of food-- only meat, mostly birds.

This male has to prove he's really good at hunting.

Hungry, dear?

A fresh meal is his way of winning her heart and showing her he can provide for future babies.

"'Kay, thanks, bye."

With a little dancing in their nest, Grinnell and Annie prepare to become parents.

This is home--the top of the 300-foot bell tower at the University of California, Berkeley.

This three-camera reality show comes courtesy of researchers who discovered Annie and Grinnell nesting here year after year.

Peregrines love tall buildings.

They give them a perch to scan for prey and a nook for their eggs.

On the cliffs that are their natural habitat, mom scratches a depression into the gravel so her eggs don't roll off.

Annie does the same thing in her nest.

In the middle of the night, she lays her first egg.

And she's not done.

With four eggs to protect, the hard work is just starting.

An unwelcome visitor drops by.

She's a young peregrine, scoping out a spot of her own.

She could be trouble for the eggs.

Grinnell is taking a turn keeping them warm, and he jumps into action.

[birds squawking] "And don't come back!"

Peregrine falcon eggs faced an even more dangerous threat 60 years ago.

Back then, the agricultural pesticide DDT accumulated in peregrines' bodies.

The chemical reduced the amount of calcium in their eggs.

Their thin shells broke when parents sat on them.

Few eggs survived.

Scientists worked tirelessly to bring peregrines back from near extinction after DDT was banned in the U.S. in 1972.

They hatched the delicate eggs in captivity and returned the chicks to their parents to raise.

Smile.

Back in Annie and Grinnell's nest, congratulations-- three hungry mouths to feed.

The fourth egg broke, maybe from lingering effects of DDT.

Mom is careful to only feed the chicks tender morsels.

By day ten, they can handle bones and feathers too.

They just cough them up.

Much better.

At a month old, they develop an attitude.

They need a ton of energy to grow their mature wing feathers.

No wonder they're "hangry."

Soon, they're almost ready to take flight.

"All right, I got this.

"And three--!

"Okay, well.

So, I'm okay!"

At six weeks, it's the season finale their fans have been waiting for.

(woman) Oh my gosh!

[crowd cheering] (narrator) The young falcons hang around the tower for at least another month, making a mess, horsing around... [squawking] and, yes, screaming at their parents.

Their story almost didn't happen.

But through conservation efforts, they're still here, keeping our cities just a little wilder.

Hey, Deep peeps, it's Laura.

It's been a tough year, but just like Annie and Grinnell, we are all trying to make 2020 work.

So check out Self Evident, a new PBS show hosted by our friend and historian Danielle Bainbridge from Origin of Everything and therapist Ali Mattu from The Psych Show.

They explore the lives of real Americans doing their best during this very weird time.

Link in the description.

And take care out there.