Original subtitles

NARRATOR: They're the unsung heroes of the animal kingdom.

It's the males that look after the babies.

These are the fathers who fly solo.

When mum takes off, they step up.

Dads doing all the work.

They start to, doing some wiggling motions and sucking their way up

on his back, until all of them are on the back of the father.

It's role reversal gone wild.

Doting dads and deadbeat moms.

He must have fallen to the ground with only one wing and walked

all the way back to his nest.

With only one parent, the stakes are high.

So what is it about these devoted dads that makes them go it alone?

Scientists have long been fascinated with this question,

but are just beginning to uncover the answers

to this evolutionary mystery.

It's one of those magical moments, rarely captured on camera.

A seahorse in the wild, giving birth.

But this pregnant parent is no ordinary mum.

In fact, it's not a mum at all.

It's dad!

The male seahorse, effectively, is pregnant and these young develop

in this pouch for several weeks.

And at the end of that development, there's tiny little seahorses

which have hatched inside the pouch and the male

will actually expel them.

Sigal Balshine is on a quest to understand why some dads

are single parents.

I study animal behaviour in the light of evolutionary

and ecological theories, so I try to really understand

what animals do and why they do those things.

She's fascinated by this exclusive caregiver's club.

Parental behaviour is probably the most intriguing

behaviour out there.

It's so variable across different animals and I find it absolutely

fascinating to think about why and how animals have come up

with such different solutions to how to look after their young.

Probably the rarest and most interesting kind of care

that's out there is male only care.

It's one of evolution's most intriguing mysteries.

When it comes to parenting, why do some males do all the work?

It's a question that has baffled scientists

ever since Charles Darwin,

who observed these strange looking creatures Down Under.

The emu is one of the most extreme examples of male parental care.

The females simply lay the eggs and then leave.

The males, on the other hand, incubate the eggs

and then take care of the chicks for up to 18 months.

BALSHINE: Charles Darwin realised that emus were sex role reversed.

But funnily enough, he said

that it wasn't just in their parenting instincts

that they were role reversed,

but he said that they were role reversed in their moral qualities.

He called females "quarrelsome, savage and noisy".

He called the males "gentle and good".

It's fairly common knowledge in Australia

that the dad emu does all the raising.

NARRATOR: Whether they're in the wild or on a ranch,

the males are the nurturers.

Emu farmer Penny Henley has a bird's eye view of this unusual lifestyle.

It's probably more surprising the fact that he is the sole parent

and I probably thought the mum had a little bit to do with it.

But, like a lot of human dads, they make absolutely brilliant dads.

NARRATOR: First comes courtship.

And it's the females who rule the roost from the very beginning.

HENLEY: You'll see the girls, they will fluff themselves up

and stick their necks out and drum around and strut around,

and then she'll get the interest of a guy.

NARRATOR: Egg laying is hard work, but her job is soon over.

Dad's work is just beginning and lasts much longer.

BALSHINE: Dads make the nest all by themselves.

They make it out of bark and twigs and sticks and grasses.

And they build this large nest on the ground and then the female

lays her eggs in that nest and he will incubate them.

He'll incubate them for eight weeks.

And during that incubation period, he hardly eats, he hardly drinks,

he hardly poops, he's just basically superdad on this set of eggs.

NARRATOR: Several females lay their eggs in his nest.

Once they hatch, his job isn't over.

He has to protect all the chicks from attacks by rival mothers.

They all want dad's attention for their own kids,

not someone else's.

When it comes to the females, I didn't know that they would

actually kill the chicks and attack the chicks as badly as they did.

As soon as the little chicks call out, every female comes racing over

to attack the chicks.

That surprised me.

I didn't think the ferocity of the attack would be there.

NARRATOR: So while a competitive mother's behaviour makes sense,

we still don't know why emu dads are the sole caregivers.

But we do have one clue.

Emus and their cousins belong to an ancient branch

of the bird family tree, where male only care is the norm.

Some scientists speculate that in birds, male care evolved first

and mums helping out only came later.

And it's not just the emu.

Sex role reversal is also part of the lifestyle

of a much tinier species, on the other side of the world.

Deep in the heart of Brazil's Atlantic rainforest,

biologists are on the hunt for another dedicated daddy.

Hidden in the leaves,

these lanky creatures are easy to miss -

unless you know what you're looking for.

Because they are so tiny and their behaviour is so intricate,

I have to pay attention really close to what they are doing.

NARRATOR: Gustavo Requena has spent 15 years researching parental care

in harvestmen - also known, appropriately enough,

as daddy longlegs.

They're distant relatives of spiders, but without the webs

or the venom.

REQUENA: We mark them individually with the animal ink.

Every individual receives an individual mark.

So, we can track where they are, what they are doing

and how long they survive.

NARRATOR: Female harvestmen have a dream gig.

Once they lay their eggs,

they're free to live the single life again.

For males, fatherhood is a seemingly thankless task.

Daddy day-care involves up to four months upside down on a leaf,

protecting a pouch of tiny, gelatinous eggs.

REQUENA: Males of this species, they can mate with a lot of females.

They stay in one plant, in one spot, waiting for females to arrive.

Females cruise the forest, looking for a love leaf.

But the attraction has to be mutual.

It's up to the female to decide who she wants as dad for her eggs.

This female is seeking a male that already has a clutch of eggs

from other females.

They're proof that he's a good dad.

REQUENA: It is at night that they mate.

Males and females can reject partners

or search and select the best mates, lay eggs.

So most of the reproductive activity happens at night.

After they lay the eggs, and sometimes they can lay two,

three, 10, 40 eggs, they leave and the male just stays

with a new clutch of eggs and his multiple clutches.

NARRATOR: Now the real work begins and it's all up to dad.

REQUENA: A really, really successful male

can mate with over 15-20 females in just a few months.

We are talking about more than 500 eggs in the same clutch.

So, when we see a really large egg clutch,

we can see different colours

because throughout the embryonic development, those embryos,

they are producing melanin, so, the old eggs, they are darker,

the really recently laid eggs, they are white, and usually,

there is this sequence from the apex to the base of the leaf.

NARRATOR: But all that care comes with a price.

REQUENA: While they take care of the eggs, males hardly eat.

So over that month, two months, three months that they stay

with the offspring, their body condition decreases a lot,

so they use the energy that they stored before they mate

with the first female.

NARRATOR: While the guys go hungry, the girls dine out.

And when females are on the prowl for a meal,

someone else's eggs can be very tempting.

REQUENA: Female of the same species, they are voracious predators.

Once they find an unattended clutch,

they basically eat as much as possible.

Where do these cannibalistic urges come from?

To Sigal Balshine, it's all about efficiency.

BALSHINE: Why would a female who makes eggs - eggs are expensive -

why would they turn around and eat them?

Well, it makes a lot of sense if they're not your eggs,

because eggs actually contain tons of nutrients and are very rich

in things like fats,

and so if you get to eat some of these, that's to your advantage,

you can turn that nutrient into your own eggs.

NARRATOR: So protecting their eggs from harm

is a key role for do-it-all dads.

The extreme sacrifices these emperor penguin dads make are remarkable.

And when it comes to parenting,

few species can match the male emperor penguin.

Although famous for their devotion,

male emperor penguins don't parent entirely alone.

But while their mates are at sea feeding,

the males incubate their precious egg alone for two months,

eating nothing at all.

These dads can lose 40% of their body weight.

BALSHINE: The female lays an egg in Antarctica

and then she leaves and goes to sea,

leaving her partner to care for the eggs.

Now these guys are caring for eggs in -40, -50 degrees Celsius.

They're just incredible, and they don't leave

and they stay there for two months

through this terribly cold period of time.

NARRATOR: Being a good father for a few months while mum's gone fishing

is one thing.

But being completely alone with the kids when mum takes off -

and never returns - is another.

In the shallow waters off the coast of Sweden,

this mysterious streamlined creature - the broad-nosed pipefish -

is well camouflaged in a shag carpet of green.

All pipefish species are special in the way that the males care

for the offspring, but they don't just care for the offspring,

they also carry the offspring on their body.

NARRATOR: Scientist Charlotta Kvarnemo wants to know why.

KVARNEMO: What really intrigues me about these fish

is how does male care evolve to this extent?

NARRATOR: To understand how they parent, Charlotta and her colleagues

have investigated how pipefish get pregnant in the first place.

KVARNEMO: First, they have a very, very long courtship dance.

They kind of just swim next to each other, check each other out,

line up together.

At one point, the females start to transfer eggs

into the male brood pouch and to do that she has a little ovipositor,

a little like a - almost like a penis that she inserts

into the male brood pouch, so the eggs get transferred

into his pouch.

The male sinks to the bottom and when he does that,

he shakes his body,.

It looks really cool, he kind of does this wriggle,

a rapid wriggle, and the eggs get shaken down to the bottom

of the brood pouch.

And right after that, he has his little stiff S posture

on the bottom.

He stays absolutely still like an S.

We don't really know what he's doing right then.

NARRATOR: Could it be the moment of conception? Perhaps.

But Charlotta has an even more fundamental question.

KVARNEMO: Why do they have a brood pouch,

when we don't see any obvious benefits of it?

Why do they do it in such a complicated way?

That's a beautiful male.

NARRATOR: Other pipefish species have a simpler method.

Males carry eggs glued to their skin.

But in broad-nosed pipefish, pregnancy and parental care

is a highly complex process.

KVARNEMO: They kind of seal up and form a very closed environment

around the fertilised eggs, that now become embryos

and start to develop.

NARRATOR: Pipefish fathers do more than just hold the embryos,

they take care of them.

In order to grow, the embryos need oxygen and nutrients.

Dad's pouch is full of blood vessels to transfer the nutrients and oxygen

to his eggs - even at his own expense.

KVARNEMO: We know that pregnant males have poorer survival,

especially a male brooding a pouch full of eggs.

Looks like he has large eggs at the top of his brood pouch

and then these small ones at the bottom.

NARRATOR: Not all pipefish are equally fabulous fathers.

Sometimes, if he's hungry, he'll absorb some of his own eggs.

KVARNEMO: He seems to be able to, in a way,

cannibalise some of the offspring and use the nutrients for himself.

We're going to keep them here in the paternity ward

until they are fully developed and ready to give birth.

NARRATOR: Some dads carry the full burden

of nurturing the next generation,

even replacing mum in the maternity ward.

But for other species, single fatherhood

is about a lot more than just tending eggs.

Springtime on the coast of southern British Columbia.

It's time for this weird looking creature -

the plainfin midshipman - to become a proud papa.

This is a species that Sigal Balshine knows well.

Every spring, around early April, the males leave the deepest,

darkest parts of our ocean,

and they make this amazing vertical migration up to the intertidal zone,

where it's shallow and there's a lot of nutrients and a lot of light

and even air exposure at low tides.

They find a rock that they really like and then they'll excavate

and they'll dig out a nice little burrow or nest

or den for themselves.

For the past eight years, Sigal has come to Crescent Beach

to research this remarkable daddy of the deep.

BALSHINE: So what you can see here

are some of these beautiful orangey-yellow eggs

and this male in this nest is the dad of all of these eggs.

The plainfin midshipman is this crazy-looking toadfish.

It looks prehistoric.

They have these light-emitting cells, about 700 or even more.

And these look like brass buttons.

NARRATOR: These glowing "buttons" reminded the scientist who named them

of a navy officer's uniform - hence the name, midshipmen.

These fish don't just look odd, they make strange sounds too.

BALSHINE: Plainfin midshipmen are considered the canaries of the sea

or the singing toadfish.

They make these amazing long, low frequency hums.

And they do it only in the spring and to attract females.

The males can hum for up to five hours, it's quite incredible.

And they'll hum for the girl fish, and the girl fish love these sounds

and they'll come up into the intertidal

and then choose the male who sounds the best.

NARRATOR: Before serenading females with song, preparation for fatherhood

involves construction work.

Males build a cozy nest by digging and removing any barnacles or kelp.

And that's only the first step in becoming a good provider.

BALSHINE: The female's laid her eggs, she goes out back to the sea,

never to be seen again until next year,

and it's dad who's stuck at home looking after the kids.

And these males will keep the eggs wet, they'll moisten them,

they'll fan them, they'll bring oxygen to the eggs with their fins.

NARRATOR: Talk about multitasking.

And it doesn't stop there.

So the males actually perform hygienic duties

and clean any diseased eggs.

When there's not anyone performing the kind of cleaning duties

in a nest, the eggs can all get diseased and die.

NARRATOR: With dad at the helm, egg-sitting under his renovated rock

can last up to four months.

BALSHINE: That's an incredible lengthy parental care period

for any fish.

And what's more incredible is they're fasting during this period.

There's nothing for them to eat in these nests

and when we open up their tummies, they're empty.

NARRATOR: What's more, Sigal's fish DNA analysis

suggests that only half of a caring dad's eggs are his own.

There are other kinds of males in the population

which we call "sneaker" males.

And these males are tiny and they're basically bags of swimming sperm

and all they do is they dash into a nest,

they turn themselves around and squirt their sperm in,

and then they dash out as fast as they possibly can.

These little males, these sneaker males,

they don't care for young, they don't court females,

they don't build a nest, they do nothing.

NARRATOR: Yet, a good father fish

will look after a sneaker male's kids.

Why would an upstanding dad compensate for this

beach bum's behaviour?

Sigal has discovered that the perks outweigh the perils.

Many, many fish that provide parental care for their young

already are guarding a territory.

He's already having to stick around looking after an area,

so he might as well look after the babies

that are in that area that he's defending.

NARRATOR: When it comes to single fatherhood,

fish aren't the only committed dads.

There are even a few amphibians who do daddy duty.

Most frogs grow up with no help from either parent.

But for these tiny frogs in a great big rainforest in French Guiana,

danger looms large.

It's a jungle out there.

I will now to try to catch this male.

so that we can take a closer look who he is

and for how long he's been around.

NARRATOR: Max Ringler and his colleague Andrius Pasukonis

study poison frogs by tracking them.

The tiny device is attached to a special pair of "pants".

OK, so these, to my knowledge,

are the only frog pants in the world.

There's a little silicone waistband that we use to attach

the transmitter to the frog,

and we're going to put them on this pretty boy here.

Now the frog is all set with the transmitter.

And with this transmitter, we can basically come any time we want,

check, find him, see what he's doing,

which frogs he's meeting, if he's transporting tadpoles,

if he's finding females.

NARRATOR: This dendrobates tinctorius frog he's just caught is a new one.

It's one they haven't marked and photograph before.

RINGLER: The frogs, they have unique belly patterns,

and with the help of an identification software,

we are able to recognise every frog in our population.

But now our database of the last almost 10 years

includes more than 2,000 individuals that we were all able to identify

just by this pattern.

NARRATOR: Allobates femoralis males are vocal,

calling loudly to attract a female.

To reproduce, the male and the female find a private spot

and deposit their eggs and sperm simultaneously.

The females will lay eggs for multiple males,

increasing the chances that at least one of the dads will be a good one.

RINGLER: The females are highly promiscuous.

On one hand, you can see this as genetic shopping,

so they try to get the best genes from all the males

that are available.

On the other hand, it's also sort of risk spreading

because once the eggs are laid, the responsibility for the tadpoles

and the eggs stays with the father.

So she's not trying to put all eggs in one basket,

just to put all the responsibility towards one male

but to spread it out across several males.

In contrast to mammals, for example, where females have to stay

with the offspring, to breastfeed them, frog eggs are just laid

in the water on the leaf litter.

So females are not specifically attached to their eggs,

which makes it easier for the males to take over the job of the females.

NARRATOR: After a few weeks, the fertilised eggs become tadpoles.

If the weather is dry, dad will do his duty -

even taking a pee on his progeny to keep them comfy and moist.

But this dad is much more than a careful caregiver.

Dad is their mobile home, transporting their tads around

to the best swimming pools.

BALSHINE: These frogs have taken advantage of the fact

that they can kind of expand into new niches.

They've gone terrestrial, if you like.

Most frogs need water and these frogs also need water,

but they found that water on land.

But on land, these pockets of water can dry up and change over time.

PASUKONIS: The main job is actually the tadpole transport,

the main and the hardest job.

The tadpoles themselves have to wiggle on the back of the male.

RINGLER: They start to suck up on their father's back,

basically doing some wiggling motions and sucking their way up

on his back until all of them are on the back of the father.

PASUKONIS: The tadpoles attach really strongly to the male.

We're not sure exactly how they do it, but it seems that it takes them

quite a while to get into a good position for the tadpole transport.

NARRATOR: No seatbelts here - just a sticky mucous to keep them glued on.

Once all the kids are aboard, dad becomes a family van.

Seeking just the right spot before dropping off the kids

at a carefully chosen pool.

But they aren't alone when it comes to this level of dedication.

There's another solo flier whose dad duties are just as demanding.

But we have to look up.

Way up, to the northernmost tip of Alaska.

WOMAN: I've always really loved birds.

In fact, my first word was "duck".

For me, it's been really a matter of trying to figure out a way

where I can make my love of birds a career.

NARRATOR: Researcher Willow English is fascinated

by the phalarope's breeding behaviour.

All right, so I'm just getting ready to weigh this bird

and make a sort of phalarope burrito here.

NARRATOR: Red phalaropes mate here every summer.

ENGLISH: So after they arrive, they start feeding

and they also start pairing up.

So females will start trying to find a male.

The males are mostly looking to find a mate and looking to eat

to get ready for incubation.

So once a pair bond is formed,

the males and females stick very close together.

So the female wants to make sure

that other females aren't going to steal her mate

and the male wants to make sure

that other males aren't going to mate with his female.

NARRATOR: Males are left behind to do all the incubation and chick rearing

on their own.

ENGLISH: The phalarope nest is just a scrape in the ground, really,

with a little bit of insulation.

He'll start making a little bit more cover for the nest,

so he'll pull some grass over it so that it's less visible.

NARRATOR: The male stays behind, trying to bundle up

and keep his kids warm on the tundra.

ENGLISH: They have to sit there for three weeks on this nest,

even though it could be snowing, it could be hailing.

NARRATOR: It can be a cold, cruel world, but here, dad holds the fort,

toughing it out in all kinds of weather.

Last year, I found a nest right when the chicks were hatching

and the male only had one wing from hitting a power line.

He must have hit the power line,

fallen to the ground with only one wing

and walked all the way back to his nest and sat on his eggs

for another few weeks,

and that really shows that they can be great fathers.

NARRATOR: Caring dads are also daring protectors,

even against enemies much larger than themselves.

It's quiet at BC's Crescent Beach - at least for now.

This midshipman has stopped humming.

Now, he's busy taking care of his eggs.

It's a tad lonely in his man cave,

but that's the least of his problems.

He's got battles to fight.

Another male is lurking nearby, hoping to make a hostile takeover.

BALSHINE: Even after a male has really established himself

and has his own batch of eggs and is being a good dad,

he's under threat from other males who want to come in

and try to take over his nest.

NARRATOR: Even if the midshipman fends off other males,

he has to guard against egg eaters, including crabs and shrimps.

The future of his developing eggs -

stuck to the ceiling of his rock nest - is at stake.

BALSHINE: These males have to deal with so much.

So not only are they air-exposed for, you know,

up to eight hours a day, but they're also bombarded by predators.

Eagles are feasting on the midshipman right now.

Herons are, gulls are.

Both mammalian predators and avian predators just hit these guys

left, right and centre.

NARRATOR: Avoiding getting eaten

is just one more challenge for these doting dads.

Sigal and her team are numbering and photographing slate tiles

to keep track of the status of males and their nests.

Later they will return to collect samples of DNA

to see how much of dad's brood is biologically his own.

After fertilising his precious clutch of eggs,

often from multiple females,

a male midshipmen has his work cut out for him.

For starters, he'll need to protect his precious progeny

from drying out.

At low tide, he'll need to splash water on his eggs

as they cling to the ceiling of his rock nest.

One thing is clear - without dads to look after them,

eggs are unlikely to survive.

BALSHINE: Any parent who provides care for their young

is taking on a cost,

an energy cost, a time cost, a survival cost.

If you're defending your young, you're more likely to get injured

or eaten by a predator.

You're spending your time running around getting food for your babies,

not feeding yourself.

It's costly to be a parent.

NARRATOR: Back in Brazil, a daddy longlegs is also on security detail.

While the females are gallivanting around the rainforest,

it's up to him - and him alone - to protect his eggs from predators.

Enemies of this light green dad include other,

bigger species of harvestmen, who could gobble up his eggs.

REQUENA: Males can attack those egg predators very aggressively.

They use a spiny appendage called pedipalps and they attack

and try to grab legs of other harvestmen.

NARRATOR: In this David and Goliath battle, even though he is smaller,

dad manages to fend off his attacker.

So the eggs are safe, for now.

But that's not the only danger.

Here comes a female.

Now, dad must play detective to decipher her intentions.

Is she looking for love, or just lunch?

This time he gets lucky and she wanders off.

It's a lot for a single parent to manage, but harvestmen dads

are surprisingly resilient.

REQUENA: What we found is that males that stay around with the offspring,

they survive more than individuals that are not associated to the eggs.

NARRATOR: So why is it better for harvestmen dads to parent solo?

Gustavo's research suggests that staying put as a dad

is less dangerous

than roaming around this predator-filled environment alone.

And there's an added bonus -

daddy longlegs has multiple mates that come to him.

Good parenting has its benefits.

But for dads toughing it out alone,

the rewards aren't always as plentiful.

PASUKONIS: It's a pretty tough world for these frogs in the jungle.

We've seen frogs with injuries from birds,

we've seen frogs getting eaten by snakes.

And we see lots of amazing things that have not been reported

or known before.

Predation events are always quite dramatic and exciting.

NARRATOR: Drama and danger are part of everyday life in the rainforest.

Remember the dad backpacking his kids,

shuttling his tadpoles to the water?

Choosing the right pool is a matter of life and death

for his little swimmers.

Danger lurks all around.

But as security guards, dads are not perfect.

Threats can be difficult to spot.

PASUKONIS: Dragonfly larvae are the really vicious predators

that will often get the tadpoles.

NARRATOR: This hungry dragonfly larva

has just had its dinner delivered by a frog father,

who failed to carefully check out the pond.

Finally, dad climbs carefully into the pool to drop off the kids.

But our dad carefully surveys the water.

He's looking for dragonfly larvae and waterbugs.

If he sees only dragonfly larvae, he will continue his search.

But if he sees dragonfly larvae and waterbugs,

he'll drop off the kids.

He knows that waterbugs will eat

some of the dangerous dragonfly larvae.

His daddy duty is done - at least for now.

If their pool dries up, he'll be back to taxi them somewhere else.

For some animals, fatherhood is an even bigger commitment.

The job doesn't end when Junior appears.

It's been a tough three weeks for this phalarope dad.

That's how long he's been sticking it out on the tundra,

sitting on his eggs.

But now the weather is warmer, the grass greener.

All his hard work is about to pay off.

At first, dad keeps his chicks warm under his body,

safe in the nest.

But these chicks are precocial, meaning they are alert and agile

as soon as they hatch.

Soon, they're checking out their new home.

Daddy only care is more common in shorebirds

than in many other birds,

where usually both mums and dads raise the kids.

In shorebirds, their chicks make it easy.

They hatch almost ready to go.

But as security guard, dad isn't off the hook just yet.

A hungry jaeger nearby waits patiently for the opportunity

to feast on the chicks.

Dad is on it and quickly hides his youngsters away.

Once the babies arrive, many animal parents don't stick around.

They don't need to.

In most cases of solo male care, like these harvestmen,

dads are primarily there to protect the eggs

until they hatch into nymphs.

PASUKONIS: So it takes about a month until the eggs complete development

and the nymphs hatch.

The nymphs stay with the clutch area for about one or two days,

and then they leave.

So there's no post hatching care from the male's perspective.

NARRATOR: The newly hatched nymphs munch on their eggshells for a snack

and a few days later, this dad's job is done.

Where the babies go to grow up, that's still a mystery.

And then there's the emu.

Back in Australia, it's the moment dad has been waiting for.

HENLEY: The little chicks do an amazing job.

And usually, once they do get out,

they won't get up and try to walk for probably 12 hours.

They just basically sit around and look at their toes

and snuggle up underneath dad, keep away from his big, hard legs.

If the dad is not real sure about what's going on,

well, he might try to peck him

or chase them underneath the feathers,

if he's concerned about predators.

NARRATOR: He hasn't had a meal or even a proper drink

for the last eight weeks, but his job is just beginning.

Fatherhood will be a full time commitment for the next 18 months.

He's more than a protector - he's their teacher,

guiding his stripy kids to a successful emu life.

The devotion of these fathers is impressive.

This rock star dad, the midshipman, looks after his own kids

and those of other dads too.

Though he'll return to the deep once the babies hatch out,

his devotion has a lasting impact.

Daddy longlegs is an extraordinary parent too,

keeping a close eye on his embryos, and by doing so,

helping his own survival.

Scientists continue to be surprised

by the complex behaviour of these wild dads.

We often think that teamwork is key to raising kids

or even that mums do the lion's share of the work.

But in nature, it's more common for parents to provide no care at all.

That's what makes these exceptional papas so special.

Why many of these star dads fly solo is a mystery still being unravelled,

but it's high time we celebrated these stay at home animal dads.