Finding the perfect partner
is tricky business in the animal kingdom.
Males must put on a show.
They'll sing and dance or compete to near death
just to win a female's favor.
But females have the final say in who becomes their companion.
There's a lot riding on making a good match.
this is a potential protector and family provider.
But all antics aside,
from brief liaisons to lifetime bonds --
when picking a mate, does "love" ever enter the equation?
[Wind howling]
NARRATOR: The Arctic.
Millions of square miles of empty ice.
Polar bears are normally solitary.
You might think that
even finding a partner in this desolate landscape
would be a challenge.
But they have an excellent sense of smell
and can detect another bear over the horizon.
Male bears can spend weeks
tracking the scent of a female
who will soon be ready to mate.
A bear's age and health
will affect its scent,
and they sniff closely to size each other up.
She's choosy.
She'll raise the cubs alone for two or three years.
It's a huge commitment.
So, it's vital
to pick a male who'll give her offspring
strong and healthy genes.
She puts him through his paces.
He's led up and down the slopes.
She's testing his fitness.
As they get to know each other,
they start to play.
Courtship is one of the few times
that adult animals play together.
This slope's rather steep for the heavier male.
It's no good, he can't quite manage it.
But she seems to have decided that he might be the one.
Yet he seems to have lost interest.
It's her turn to do the chasing...
and she's got a few tricks to reignite his passion.
He rouses himself for a closer look.
Now that she's reeled him in,
she goes straight back
to giving him the run-around.
Playing hard-to-get can reveal
how fit and strong potential partners are --
a useful strategy, and not just in polar bears.
It's often the females who do the choosing
and the males who have to make
all the effort.
In the tropical forest of Papua New Guinea,
one male is dedicated to making that all important
first impression.
The six-plumed bird of paradise
begins with meticulous housework.
He obsessively tidies
every fallen leaf.
He's hard at work creating a stage
for what will be quite a performance.
A few berries decorate the floor.
His final touch is hardly ever seen.
He appears to have found a bit of old snake skin.
Some scientists believe
he's trying to add the scent of a snake
to ward off predators.
For others, it's a cleaning cloth,
and he's polishing a perch for a female.
Later, he comes up with a bigger rag
and does the same.
Only strong, healthy and well-fed males
can afford the time and effort
for this most meticulous preparation,
and in theory, they're the ones with
the better genes to pass on.
He'll have a highly critical audience.
So, it's time to rehearse the main act.
[Jazzy score playing over]
His dance steps perfected,
he's ready to start the show for real.
He spots a female nearby,
so quickly goes to get more berries
to tempt her in.
Disaster!
He's left his polishing rag on the dance floor!
It's perfect for her nest!
She flies off without even seeing his dance.
He delivers his berries too late.
He never got the chance to win her heart --
and she stole his polishing cloth!
Back to work.
As fussy females favor particular attributes,
they become exaggerated over generations,
leading to ever more elaborate and extreme displays.
They are full of clues
as to how good the male's genes might be.
[Birds calling]
It's all a matter of taste.
Different species are attracted to different features --
fancy feathers,
red faces,
blue faces...
large noses...
Beauty is all in the eye of the beholder.
It's often a special costume, or dance,
or even an exotic perfume that can turn heads.
In the forests of Madagascar, it's all three.
Welcome to the lemur lounge bar.
The boys are on parade, hoping to be chosen.
They are sizing each other up
this morning, with calculated disdain.
One of the females is in heat.
The breeding season is short
and who gets whom is all up for grabs.
Fights quickly break out.
The object of their affection just sits and waits.
While the fur flies, one sneaky young male
sees an opportunity to make his move.
He hopes to win her heart by more subtle means.
With an air of nonchalance,
he settles down and begins to smear scent
onto his tail from glands on his wrist.
The perfume he wafts over her
will tell her a lot about
what he has to offer as a potential partner.
And he might just offer something
that the other males don't.
He may not be the strongest fighter,
but the latest science suggests his scent might contain clues
to a different strength --
his ability to fight illness and parasites,
which he could pass on to her offspring.
She's still not convinced.
Maybe she should wait for the arguing males to finish.
[Male lemurs squabbling]
But the quarrelling continues, unresolved.
So, she leads him off somewhere quieter.
His offer has finally won her over,
and they indulge in some undercover love.
Extravagant dance, flashy colors
and irresistible perfume may all be clues
to good genes,
but occasionally a male has to offer more.
On the other side of the world,
an idyllic English riverside
is the setting for one such story.
Here is a creature who seems to flirt with suicide
to woo his paramour with the perfect gift.
The delicate banded demoiselle
knows that what every girl wants is fast-flowing water,
rich in life-giving oxygen,
as the best place to lay her eggs.
Each male, in his shining metallic armor,
is prepared to fight for the best patch,
in a graceful aerial contretemps.
The victor has won possession of a place
where the river riffles round a fallen branch.
Faster running water --
that's just what the ladies are looking for.
But how can he prove that this is a good spot?
He flings himself at the water,
using his own body to show the flow.
It's a high risk strategy --
he might drown, or be snatched by
a hungry fish.
If she's impressed,
she'll allow the seduction to conclude.
All his hard work
has paid off.
She gives their eggs the best possible start in life,
laid on plants
in oxygen-rich water.
He's a true romantic hero
who's risked his life,
and all to offer a lady
the perfect place to lay her eggs.
But there are times when males offer something
that seems almost arbitrary.
Topi, African antelopes,
gather each year for a very unusual
and highly ritualized contest.
The males start by putting on war-paint.
By plastering their horns with mud,
they're trying to be more intimidating to other males,
and maybe more attractive to females.
The dirtier the better.
The males compete in a loose circle,
called a lek,
and each fights to hold ground as close as possible
to the center of the arena.
Gaining a coveted place on the lek
signals that a male is fit enough
to out-compete the others.
He's stronger, more determined --
a winner.
The lek is a constant battlefield
for the duration of the mating season
as males continually challenge and defend.
The females are most impressed
with the males at the heart of the arena,
and reward them accordingly.
The topis' rituals go on for many days.
The males dare not leave their territories,
or rivals will claim them.
As the days pass,
they become ever more exhausted.
For some, the competition exacts
the ultimate price.
Hyenas are quick
to take advantage of the weak and exhausted topi,
particularly on the edges.
We can see now why the females
find the topi in the middle more attractive.
The center is very much worth fighting for.
Yet despite the hyenas,
the male topi stay close to their positions on the lek.
To flee would mean losing any chance of mating.
[Hyenas squabbling]
To make sure that they win any contest with their rivals,
many males weapon up.
[Bellowing]
Full of testosterone and belligerence,
males push each other to the limit.
But fighting is a dangerous, even life-threatening, strategy.
So, animals will go to great lengths to avoid a fight
if they can.
American bison graze peacefully together
until the mating season arrives,
when the atmosphere changes.
The males begin to
"taste" the air, to pick up the scent
of any female who might be ready to mate.
Before any fight, competing males strut
alongside each other,
assessing one another.
Pumped up with testosterone,
they paw the ground to show off their strength.
They spray the earth with their urine
and then roll in it,
so they reek of their own hormones.
These ritual displays can put off rival males
without having to resort to a potentially dangerous fight.
But it doesn't always work.
Even then,
most fights are resolved in a matter of seconds.
A few, however,
escalate into full-scale battle.
Weighing almost a ton,
they use power and speed
to try and push each other off their feet.
This male is lucky to escape a fatal stabbing.
For the winner, the prize is the whole harem of females.
Whether by fighting or by more sophisticated means,
it's often males who seem to do the hard work.
But it's not always as one-sided as you might think.
In the mountains of Central Africa
live gorillas.
Extended families
of females and youngsters
are headed up by a dominant male,
the silverback.
He defends his territory
by intimidating any rivals from among his neighbors.
Fights are rare,
and as with bison, there's a lot of bluster.
Males also hope to impress neighboring females
with displays of strength,
tempting them to join him,
while keeping the neighboring silverbacks
well away.
He's attracted
a new young female.
It seems she wants this silverback
to father her children.
She only has a day or two when she's fertile.
There's no time to waste,
but she's going to have to work hard to get his attention.
She stares at him,
a brazenly flirtatious act in itself.
She tightens her lips into a smile
and gazes straight into his eyes.
This is gorilla seduction at its least subtle.
But he doesn't seem to be won over
by her shameless tactics.
Now what's a girl to do?
The whole family watches to see what happens next.
The young female decides to try
a different tactic.
There are two teenagers,
black-backed immature males,
and she flirts with them.
She positions herself between
the two rival boys.
Both are interested in her.
She's a tease.
As she joins one,
the other watches, grunting in jealous fury.
She solicits both males,
but doesn't actually mate with either.
She only has eyes on the big prize,
and sure enough, the silverback hears
and comes charging in.
With a little subterfuge,
she gets her man.
[Grunting]
The silverback will offer
more than just good genes to her offspring.
Any children that are his
will get his protection as part of the family.
Perhaps best to make absolutely sure.
It's all for this --
a helpless mountain gorilla baby,
one of only a handful left.
The family bonds among mountain gorillas are strong.
The silverback's role as father goes beyond protection.
He's babysitter, playmate,
and role model, too.
When both parents stick around
to protect and rear the offspring,
finding the right mate becomes more complex.
It's no longer just about strong and healthy genes,
but more about being a good father.
Dads offering worthy parenting skills
can be found in the most unlikely of places.
Spring in the sea off Australia.
Below the surface
lies a dedicated father, a weedy sea dragon.
His outfit is unusual for a fish,
with colors and dots and strange attachments.
He's a cousin of the sea horse.
When he finds his weedy sea dragoness,
he joins her for a dance.
As the evening progresses, she leads him on a slow waltz.
In a graceful duet, each partner mirrors
the actions of the other.
They sweep and they wiggle.
Darkness will soon draw a veil over the pair,
but they will dance on into the night.
Two months later,
and the nature of what he was offering is revealed.
After the dance, the female transferred all her eggs to him.
Since then, he alone has cared for them.
By embedding them in his tail and carrying them everywhere,
he has kept them safe.
And now, they start to hatch.
In the calm of a summer morning,
a baby weedy sea dragon is born,
its yolk sac still attached.
The babies shelter in the weed bed,
now feeding themselves.
Their success is thanks to a father that stayed around.
Many other animals
test for parenting skills with a pas de deux,
but flamingos go dancing on a much grander scale.
[Flamingos squawking]
The party here on Lake Bogoria in Tanzania
is perhaps the greatest gathering of courting couples
in the animal world.
Thousands of flamingos dance together,
all looking for Mister or Missus Right.
Eye color and bright feathers are important --
the redder, the better.
Once you've caught someone's eye,
it's about choosing a partner who will be loyal,
who will stick around.
Flamingos like partners
of their own age and size.
But the dance may reveal much deeper insights into each other.
Many animals find symmetry attractive,
and the mirrored movements and coordinated head turns
may help find a mate that is more compatible.
They seem to prefer birds like themselves.
It's vital to make the right choice.
Flamingos nest
in the middle of soda lakes.
They are swamps of caustic mud,
and among the hottest places on Earth.
It's a trek to find the nearest food and water,
and you can't leave the nest
to bake in the sun.
That means raising the chick
is impossible for a single parent,
and working together is crucial.
It gets above 120° out here.
This is parenting at its toughest,
so the choice of partner made in the dance needs to be right.
There are many animals for whom the choice of mate
is really about finding a partner
to look after the family together.
But in some cases, that doesn't work out well for everyone.
[Howling]
[Wolves howling]
February in Yellowstone --
bitterly cold and food is scarce.
Teamwork is what matters to wolves.
Their prey, elk,
are many times a wolf's size.
The wolves must work together,
so their offspring stay, often for years,
hunting, and helping raise the pups.
This works well for the wolf parents,
but not quite so well for their older offspring.
The leading couple discourages the teenagers
from looking for a mate.
But one of their daughters has romantic ideas of her own.
Skulking behind the pack is a lone male wolf.
He has no territory of his own,
but follows the family, scavenging leftovers
and looking for opportunities.
He's spotted one --
the young daughter.
The intruder stands a good chance with her,
as long as he's not caught.
The pack leader could kill him.
[Howling]
While the pack is distracted by a bison,
the temptation for the young female
is too great, and she sneaks away
to join the mysterious stranger.
It's risky, but it could be her only chance
to hook up with a potential mate.
When mating, wolves lock together,
unable to separate for half an hour,
to ensure fertilization.
Not so good if you're about to be caught
by your dad.
The affair was always destined
to be a short one.
After a painful separation, her new mate is chased away
with his tail between his legs.
The wayward daughter is chastised for her behavior.
Eventually though,
she'll be accepted back into the family.
Had she not been caught,
she could have played the innocent daughter...
at least until any pups were born.
It is not unusual
for animals to want their private lives to remain private.
[Howling]
The more we learn about how animals behave,
the more it seems that
behind the facade of seemingly perfect animal partnerships
lurk darker secrets.
The truths of which are only now coming to light.
Lar gibbons, in the forests of Thailand.
They seem to be the perfect couple,
monogamous and musical.
[Calling]
Their duet is
a renewal of their partnership,
and proclaims their home territory.
They stay together
to raise a family.
But appearances
can be deceptive.
They're surrounded on all sides by neighbors,
and gibbons can sometimes stray.
It turns out
about one in ten matings is not with their partner.
Some scientists think that there may be a reason
for a female's infidelity.
A quick liaison may serve to convince other neighboring males
that they could be the father of her offspring,
and this might stop them attacking the youngsters.
Maybe a little infidelity
actually helps protect the family.
Whatever the reason for straying,
their affairs don't seem to be a problem for their partnership.
They'll remain together.
Animals seem to distinguish
the partnership they need to look after a family
from the affairs along the way.
But while some animals tolerate infidelities
and seem to turn a blind eye,
others notice and remember.
On the Galapagos Islands,
blue-footed boobies are just starting their families.
Blue-footed boobies also dance to form partnerships.
Each movement mirrors the other.
Like flamingos,
they seem to fall for birds like themselves --
compatible.
"Booby" means "clown."
Their big blue feet
are an important part of the costume.
Blue feet are important because the blue color is hard to make,
especially if the birds are in poor condition.
It's an honest indicator of good health.
So, they show them off.
Unlike flamingos,
boobies continue their courtship displays
even after nesting starts,
as though they weren't quite sure of each other.
And then,
while their partners are away feeding,
both sexes flirt with
their neighbors.
The truth is that boobies have a roving eye,
and those blue feet tend to wander.
About half have secret,
extra-marital affairs.
They come up to each other and display.
And one thing leads to another.
Occasionally, the male comes back
and sees the female with someone else.
She quickly returns to his side.
He doesn't react!
They display, as they always do,
affirming their relationship.
They never split up.
It seems here the instinct to stay together
to raise the family
is stronger than any infidelity.
But nobody wants to bring up someone else's chick.
He remembers what he saw and seems to count the days.
If an egg is laid five days
after catching his partner with a neighbor,
he knows he isn't the father.
When she's away,
he'll roll it out of the nest to be lost.
She returns, and their relationship keeps going.
She'll lay more, and once the eggs hatch,
they'll settle down to a faithful
family life.
So, does everyone cheat at the mating game?
Well, maybe not.
Animals that stay together forever and remain faithful
are certainly very rare.
But there may be a few perfect partnerships.
One may be found in New Caledonia
in the South Pacific.
These are kagus,
flightless birds that stay together as a couple for life.
Both parents work together to look after one chick.
This is Dad, pitting his wits against a worm.
Spot the chick.
The camouflage is effective.
Less effective is getting the food in.
Feeding babies can take a lot of patience.
Some of the young from previous years
stay in the territory
and help defend any chicks
from predators or neighboring kagus.
[Calling]
Each morning
they spend about 15 minutes singing together.
They work as a team and chase away any intruders.
The kagus' relationship is solid
and their bonds of commitment
are passed down to the offspring,
forming a really strong
family unit.
But the kagus also seem to be quite the romantics.
Each year the male
rekindles the flame with this life-long mate.
She's seen it all before,
but it's still important to remind her.
After all, no one likes to be taken for granted.
They may be committed for life,
but it seems he still wants her to know
that she's the only one for him.
Throughout the animal kingdom,
the mating game is full of extraordinary behavior
and surprising sophistication.
Even fighting
is overlaid with ritual
and sacrifice.
For many animals it's all about
playing the field.
Some are carefully chosen
for a brief liaison.
But there are those searching for commitment,
a partner who will stick around.
While others form bonds that can last a lifetime.
There are even a few that remain truly faithful.
Though we can never be sure what animals feel,
sometimes,
it looks like love.
And it's hard to know, then,
what else to call it.
Back on the soda lake in Africa,
the flamingos have left their nests.
Left behind, a couple.
One is stuck,
helpless in the mud.
The other flamingo could fly away at any point.
The chicks are gone, their job is done...
but they stay,
together, to the very end.
To learn more about what you've seen on this "Nature" program,