Nature (1982–…): Season 35, Episode 1 - Super Hummingbirds - full transcript

Nothing in the world
is like a hummingbird.

Their abilities border
on the magical.

Though they're the
smallest birds in the world,

they generate such speed,
they appear to alter time.

Now with ingenious science
and high-tech imagery,

we're beginning to understand
their deepest secrets.

Beneath their tiny,
brilliant feathers,

they are kung fu fighters,

tender mothers,

and some of the most
dazzling aerial dancers

in all the world.



You're about to enter the
hummingbird dimension,

where life moves faster
and shines brighter

on these super little birds.

Hummingbirds seem to
spring from the imagination.

Small and bright,

they have abilities no
other creatures possess.

Time seems to bend for them.

They float suspended
or fly backwards.

Their wings beating
faster than the eye can see.

They appear and
depart with such speed,

you're not sure
you saw one at all.

Yet hummingbirds
are made to be seen.

They catch the light.

A flash of emerald,
a glint of sapphire,



a blaze of ruby.

These sunlit jewels
evoke such wonder,

we struggle to describe them.

The tourmaline sunangel.

The sparkling violetear.

The long-tailed sylph.

The green-crowned woodnymph.

The wire-crested thorntail.

In real time, they're
often long gone

before we can say their names.

Almost everything
about hummingbirds

has been shaped
by lifelong partners

they can't do
without... Flowers.

Hummingbirds are found
only in the Americas,

and all through their range,

flowers have come
to rely on them

for an essential service.

They need a go-between
to carry their pollen

to another flower
of their own kind

so they can reproduce.

And so they dust a visiting
hummingbird's forehead

with pollen, and the bird
flies from flower to flower,

pollinating as it goes.

So close is their partnership,

many blossoms have become

a custom sleeve for
hummingbird builds.

The flowers have
gambled their future

on the little birds.

Other pollinators
who don't fly as far

and as fast need not apply.

The hummer's reward is
sweet, nutritious nectar...

Their favorite food.

Nectar is the high-octane
fuel that keeps them in the air.

But their fuel
tanks are so small

and their burn rate so high,

a fill up only lasts
them 20 minutes.

A hummingbird among
flowers is on urgent business,

zipping from bloom to bloom,

seeking nectar before
she runs out of fuel.

But no one had ever looked

at what happens inside a flower

when a hummingbird
actually drinks

until a young graduate student

designed some ingenious
flowers of his own.

Ooh, it's a mango.

Nice.

Alejandro Rico-Guevara

and his wife, Kristina Hurme,

met while they were PhD students

at the University
of Connecticut.

She's a behavioral ecologist,
and he's an ornithologist.

It's great.

It's Alejandro's
research into the form

and function of hummingbirds

that has brought them
back to the mountains

of his native Colombia.

My passion is studying

how animals look and relate
that to what they actually do.

So, in the case of hummingbirds,

we didn't know what they
were doing inside the flower,

and everything that
makes a hummingbird

what it is is
feeding on flowers.

To peer into a flower

and see what's really going on,

Alejandro needs a camera
that can record at high speed

and a most unusual flower.

How's it looking for you?

It looks awesome.

It's advertised
with a flower sign

hanging out in front

that helps guide the
hummingbird's bill

to the nectar down in the tube.

I can control how much
nectar is in the chamber.

And that chamber is
made of glass slides

to prevent distortion
for the camera.

We're all set there.

Hope it works.

In no time, his flower
has a customer...

A white-vented plumeleteer.

Instead of drinking through
a straw-like structure,

as many insects do,

hummingbirds lap nectar
up at an astonishing rate

of 20 times a second.

Their tongues move
almost as fast as their wings.

Okay.

It's all set up on this side?

Yeah.

Alejandro's transparent flowers

mimic not only the shape
of actual nectar chambers,

but also the amount of
nectar the flowers contain.

The plants don't
want the birds to linger.

Their aim is to keep the
hummers on the move,

seeking out more plants
of the same species.

In just a second or so,

a hummer has
lapped up all the liquid

the little chamber offers

and moves on in a constant
dance among the flowers.

But how is it possible

for a tongue thinner
than a fishing line

to perform such a feat so fast?

Inside his workshop,

Alejandro is creating
something special.

He's mounting a real flower

on to one of his
clear feeding tubes

with a cutout on the side...

A window to the
inside of the flower.

Now with high-speed
macro photography,

we see something truly new.

Hummingbirds' long
tongues have forked tips

that open as the tongue
dips into the nectar.

A fringe of tiny filaments
uncurls along the edges

of the open tips,

creating grooves
that spring open,

filling the tongue with nectar.

It's a structure science
has never seen before,

and it's an incredibly
efficient technology

for picking up a liquid.

He's right there.

It was Alejandro's
resourcefulness

and the painstaking work

he began as a grad student

that has revealed something
science had never imagined.

An unusual tongue
is just the beginning

of how flowers
influence hummingbirds.

Feeding on flowers
has shaped everything

about the way they fly.

To sip on nectar,

hummers have had to master

the most challenging
feat in the air...

Hovering.

Hovering requires hummingbirds

to beat their wings up
to 80 times a second.

Like insects, hummers gain lift
on both sides of a wing stroke,

but their method is unique.

Handicapped by
bones and feathers,

they use their skeleton
in a clever twist.

Even at 600 frames a second,

it looks as though they flip
their wings at the shoulder.

But their arm bones are so
tiny compared to other birds.

Their wings are
more like giant hands,

able to rotate
from a flexible wrist.

Back and forth,
they scull the air

as though treading water,

hovering almost indefinitely.

They can stop or
accelerate in an instant,

lift straight up or down,

and pivot in any direction
a breeze takes a flower.

The search for nectar keeps
them constantly in the air.

They live right at the edge
of the energetic tradeoff

between how much fuel
they need to power their flight

and the flight they
need to find more fuel.

Living on such a tight budget,

it's a marvel that
their stronghold is here

in the wild terrain
of the Andes.

But hummingbirds'
affinity for mountains

is written in their genes.

Some 10 million years ago,

as the Andes began to
reach their rugged heights,

they created many new worlds in
which flowers and hummingbirds

began to proliferate.

Today there are 338 species,

and they are still evolving.

Yet how they keep their
demanding metabolisms humming

in the thin air at 16,000 feet

has been a longstanding
biological mystery.

It's a pretty good
place to perch it

if you want to control a
piece of this valley here.

Dr. Christopher Witt of the
University of New Mexico

has set up camp at
a high valley in Peru.

He and his team
risk altitude sickness

at these heights, all to find
out the hummingbird's secret.

Hummingbirds are
just these spectacular

metabolic machines.

When hummingbirds are hovering,

they have the
highest metabolic rates

of any vertebrate.

How can they sustain
such high metabolic rates

when oxygen is so scarce?

40% more scarce
than it is at sea level.

This is a fundamental paradox.

Why would these
birds be so successful

in these cold, rugged mountains?

To find out, Chris
has to catch some.

See these shrubs up here?

We've got tons
of nectar, flowers.

He sets up a couple of mist nets

that will entangle the
birds without hurting them.

There we go.

There's a couple
birds moving there.

It's not long before
they have a catch.

Excellent. Looks
like a black metaltail.

Beautiful. MAN:
Yeah, yeah, we got it.

It's a sparkling violet here.

Looks like it's in great shape.

Looks like we got a
shining sunbeam over here.

Beautiful.

That's why they call
it a shining sunbeam.

It's a giant hummingbird.

This has got to be a big male.

It's 10 times the size of
a calliope hummingbird

right there. It's incredible.

They've assembled
quite a variety

of high-mountain hummingbirds.

Now Chris' carefully
designed test flights can begin.

I think it's just human
nature to be interested

in the limits of performance.

We want to know what's
the most that a bird can do?

What's the extreme
in terms of flight?

So, this is the
sparkling violetear.

Right now, the bird is sort
of figuring out the confines

of its new chamber,

but it's gonna spend
most of its time

on that brass perch.

Oxygen forms about
21% of Earth's atmosphere.

Bit by bit, Chris will reduce
the percentage of oxygen

in the chamber to simulate
an increase in altitude.

I'm gonna ratchet
the oxygen down

by infusing nitrogen.

So, we're at 13%.

And the fact that it's
hovering a lot is evidence

that it's not having
very much trouble.

I would say it's
nowhere near its limit.

Now the test gets harder.

There we go. 11%.

The violetear is asked to fly

by temporarily
removing her perch.

I'm so darn impressed
with her athleticism.

It's now 7.5% oxygen.

She's having trouble.

That's an amazing
feat right there.

Bird did an amazing
job producing lift.

It's not until the
gauge drops to 6%

that she truly
reaches her limit.

That's an altitude
equivalent of 43,000 feet...

Well above the cruising
limit of a jumbo jet.

But she still tries to fly.

That's incredible. I can't
believe she can do that.

Chris knew there had
to be something special

about hummingbird physiology

to enable the violetear
to perform so well

with so little oxygen.

He discovered that a
protein called hemoglobin,

which we all have in our blood,

has evolved in each
hummingbird species

to match its elevation.

For these hummers
in the high Andes,

they can grab scarce oxygen
molecules like a magnet.

Now the giant sits
in the chamber...

A true high-altitude specialist.

The current amount of oxygen,

it's enough to send a human

who's not acclimatized
straight into a coma.

Perfect. Wow.

The giant is finely
tuned to thrive

where oxygen is scarce.

Here in the high Andes,

that gives it a strong advantage
over other hummingbirds.

This is my favorite part.

We're gonna let this
bird go back home.

Fly free.

Straight up slow. I love it.

All the hummingbird species

that live at high altitudes

are just better at
performing in thin air.

And remarkably,
Chris and his team

found that all hummingbirds

have some degree of this
amazing oxygen capacity.

Even in the lowland rainforest,

many of the hummingbird
species can easily withstand

a reduction in oxygen

that's equivalent to climbing
to the peak of Everest,

which is a shock to us.

That's a testament
to how well designed

their respiratory system is.

Chris and his team
have discovered

a real hummingbird superpower,

an ability to capture extra
oxygen with every breath.

This is what makes it possible

for hummingbirds to
produce such dazzling speed.

And they need all that power,

not just for feeding on flowers,

but for fighting over them.

Flowers in full bloom
are a call to arms.

It's fight and flight.

A display of skill
and fiery tempers.

The bills they dip
daintily into flowers,

they now wield as weapons.

Gravity means nothing to them.

High-speed maneuvers
are a show of force.

Wheeling, colliding,
flying backwards.

Now they push
themselves to the limit.

Hearts racing at
1,200 beats a minute,

lungs bursting.

They spend every last
molecule of oxygen,

every ounce of fuel.

But at 500 frames per second,

their battles are a
breathtaking ballet.

Now and then, one
stops at a flower

for a sip of energy.

Or tries to.

10 gulps of nectar
in half a second,

and then back into the fray.

A long-tailed sylph
sits on the sidelines.

His dazzling blue tail is
at least as long as he is,

but no help in a fight.

Flower after flower,

he attracts the unwanted
attentions of chestnut coronets.

At last, he gets the
better of a little woodstar.

Then the coronets are back.

There's a brief
moment of detente,

aided by the flower's
clever architecture.

But it doesn't last.

The sylph finally retreats.

The coronets all together
are too much for him.

A tiny wire-crested thorntail
is having a similar day.

But she's so small,

she may be able to hide
among the honeybees.

And just maybe the bees will
let her have a sip of their flower.

As the day draws to an end,
hummers face a dilemma.

They need to rest.

But even asleep, they'll
burn too much energy

to survive the night
without constant refueling.

So they do the
only thing they can...

They shut down and
enter a state beyond sleep.

It's called torpor.

High in the Andes,

a giant hummingbird
sits motionless,

snuggled deep into his feathers.

His usual high-speed metabolism

slows by as much as 90%.

His heart rate drops
from 1,000 beats a minute

to a mere 70.

His temperature falls
from a feverish 104

to 46 degrees...

Close to the ambient
nighttime temperatures

in these high mountains.

It's a state similar
to hibernation,

a winter he endures each night.

Far above, a vast
universe sparkles and spins

while hummingbirds everywhere
brilliantly conserving energy

wait for dawn.

It's a new day,

and we're no
longer in the jungle.

This is the Sonoran Desert,

and even in the early morning,

heat waves are rising.

Surely this is no place
for a hummingbird.

But a pioneer has ventured here.

The flash of magenta
reveals the little hummingbird

to be a costa's, a
desert specialist.

He's tough enough to handle
the desert's arid conditions,

and the Sonoran
is rich in plants

that flower all winter long.

Sitting high on
a favorite perch,

he scans the landscape
for something special.

And there she is.

A female costa's.

Spring is the time to nest

before the desert gets too hot.

Both birds are
looking for a partner.

But the choice of
mate will be hers.

It's up to him to impress her.

He moves in close,

hovering directly
in front of her,

rocking his entire
body back and forth

in a display of flying prowess.

Though his back
shimmers with green,

it's not until we
get her point of view

that we see his true splendor.

He flexes the iridescent
feathers of his mantle

until they become a
glowing mask of violet.

Facing into the blazing sun,

he swoops back and forth,

his face a fiery
flower before her.

How can she possibly resist him?

And yet she does,

leaving him to
return to his perch.

Perfecting his performance
is going to take some practice.

But what if he must woo a female

in a dark, dense jungle,

where just the right
lighting is hard to come by?

The long-billed hermit

has solved that
problem with song.

And although they don't
carry much of a tune,

they can belt out quite a
strong and distinctive chirp.

Marcelo Araya-Salas
of Cornell University

has spent seven years in
the rainforest of Costa Rica

studying the vocal
stylings and mating rituals

of the long bills.

As in many hermit species,

the males form a chorus.

You can actually hear
one bird over there.

There's one bird here.

Two or three in this area.

Marcelo is standing in
the middle of a hermit lek.

A place where
males come together

to attract and
compete for females.

This lek is a stage
for 9 or 10 singers,

and as small as they are,
their voices carry across an area

of some 300 by 450 feet.

It's not a free for all.

They listen carefully
to each other

and then chirp into
the rhythm of the group,

alternating their own
calls with the others.

Although they're in competition,

every voice gets its
moment to be heard.

You see those two birds?

It's a pretty active time

because they're just
coming back from breakfast.

They have breakfast
around 6:15 to 7:00,

then they come
back pretty energetic,

and they're singing a
lot for two or three hours.

Singing is just the
beginning of the show.

Elaborate choreography
comes next,

and to see that,
Marcelo sets up cameras.

He's recorded thousands of
hours of intense hermit society.

The singers are
all resident males.

They're mature and strong
enough to hold a territory on the lek.

Looks like some
interaction right there.

But instead of a female,

the first to arrive is
often a challenger,

perhaps a young male
looking to take over this spot.

A strange and
beautiful duel begins.

It's ritualized combat
conducted face to face.

The perch owner sees
a challenger approach

and starts a tail fan.

When the challenger alights,

the resident begins
a float display,

hovering smoothly back and
forth directly in front of him.

They take turns, each
trying to outdo the other.

Sometimes they add a bill pop.

Flipping their heads up
while making a popping sound.

And it all typically
ends in a chase,

the winner chasing
the loser away.

All over the lek,

performers compete
for hours a day,

some eight months
out of the year,

and it's all for this.

The moment when the intruder

is not a challenger,

but a female,

and all the moves
perfected by the contest

with other males
are performed for her.

In more than 2,000
hours of research video,

this is the only mating
Marcelo has recorded.

It's certainly one of the
first hummingbird matings

ever caught on camera.

After the brief
encounters of the sexes,

it's the females that
take over the story,

crafting one of the
wonders of nature...

A hummingbird nest.

These two hermit chicks

have spent their first
three weeks of life

at the tip of a leaf,

protected from the rain
by its wide green awning.

Now they are almost
ready to fledge.

All their care and feeding

have rested on their mother's
tiny feathered shoulders.

But her first task of motherhood

was to build them
a remarkable home.

A rufous tail has begun her nest

on the underside of a palm leaf.

Its spiny defenses are
hummingbird-sized branches,

perfect for her to weave around.

Her materials are
fragile and light.

She can only use what
she can carry on the wing.

Soft plant down is wrapped
in long, green strands of lichen

and other plant fibers.

Bits of leaves are tucked in.

Stretchy and strong,

the nest takes shape around her.

As she builds the outside up,

she tamps the inside down

using her feet to shape a bowl.

She binds it all together

with layers of
sticky spider silk.

The project will take her five
to seven days to complete.

When done, it's a perfect
little cup, snug and warm.

It's finished just in time.

Before dawn, she settles in.

She's ready to
lay her first egg.

It's an enormous effort
for so small a body.

Her exertions are
rewarded at last

with one gleaming white egg.

She leaves it to dry and harden.

And returns the next
morning to lay a second.

For the next two weeks,
she will patiently sit,

an iridescent flash
in a rested motion.

She will feed and
rest, feed and rest,

building her strength
for the job to come.

Rain is an almost daily
occurrence in the tropics.

Hummingbirds don't seem to mind.

Neither rain nor thunder
stays these little wings

from their appointed flowers.

And they don't take bird baths.

They take showers.

When you're so small, a
little water goes a long way.

This glittering-bellied emerald

seems to enjoy a
little splashing around.

A chance to shake things out

and put them
neatly back together.

But for hummingbird
mothers, there's never a break.

Feeding themselves
is a constant effort.

Now one hummer
must support three.

And baby birds need
more than nectar.

They need protein.

For that, hummingbirds
go hunting.

Their prey, though
almost too small to see,

provide the extra boost
all hummingbirds need.

They often emerge after a rain.

Tiny insects rising
on the warming air.

Hunting takes practice
and preparation.

A violetear makes sure
her feathers are primed

and ready to go.

She works from a perch with
ample air space overhead...

A good hunting ground.

The first few runs
are often misses.

Sometimes the catch
is a nasty surprise.

But she tries and tries again,

for inside every flower feeder,

there lurks a bird of prey.

A good fly-catching
perch is prime real estate.

Some indigo-capped
hummingbirds attempt to move in.

And a brazen rufous-tail
wants it for himself.

For hummingbirds,
everything is a competition.

Above all,
hummingbirds are restless

and in perpetual motion.

A t least twice in
their very long history,

their constant search

for opportunity turn them north.

From deep in their South
American stronghold,

they cross the isthmus
into Central America.

Then in a second
wave of colonizing,

they began to push across
the border into the U.S.

and up into Canada.

Only 17 species have
made it to North America,

but they are resetting
the boundaries

of hummingbird country.

100 years ago,
Anna's hummingbird

spread only in Baja
and southern California.

But in just a century,
their breeding range

has expanded north
along the West Coast

all the way to the
Canadian border.

Today, some are
permanent settlers,

spending the winter as far north

as the temperate rainforests
of the Pacific Northwest.

Other hummingbirds migrate
long distances each year,

arriving from wintering grounds
in Mexico and Central America

to breed in the mountains
of the American West

just as their flowers bloom.

A female broad-tailed
hummingbird

has already started
this year's family.

In her remarkable care,

two little hummingbirds
emerge into the world.

They are blind, almost naked,

and utterly helpless.

Their mother begins
their upbringing

with a continuous supply
of nectar and insects,

the fuel that will power them

through their entire
high-speed lives.

Hatched a day apart,

they don't look like
much at the start.

But these homely,
hungry little creatures

have been born
with astonishing gifts.

In just three weeks,
they are transformed.

They barely fit in the nest,

which is already stretched
to accommodate them.

Though growing fast,

they still have their
short baby beaks.

Content in their mother's care,

they may have no
thought of the wider world

that awaits them,

or that they will
be able to fly.

A male broad-tail,

his gorget rosy red in the sun,

dips into flowers nearby...

A vision of the future.

Now they've
discovered their wings.

They just need room to practice.

They're tapping into
powerful new muscles

they can't quite control.

But her little wings
have come to the rescue.

Her recovery from near
disaster has made her bold,

and she flutters
down the branch,

away from the nest.

With one chick out,

the second is soon to follow.

But they're not on
their own just yet.

Their mother still
provides for them

with a demonstration
of perfect flight control.

Then suddenly, they're gone

with a flash of tiny wings.

They join these
master works of nature,

magic in the air,

dazzling in the light.

Science and technology have
struggled to catch up to them.

How's it looking for you?

Only now are we discovering

the genius of their adaptations,

the full extent of their powers.

And they're not done yet.

Hummers are still evolving,

still becoming like no
other birds on Earth.

The more we know, the
more fascinating they are.

And so we will follow
them the best we can

as far and as fast as they fly.

To learn more about
what you've seen