Narrator: We know a leopard can't change it's spots,
But what about giraffes?
Midcap: It really does look like a mythical creature,
Where did this come from?
Narrator: Why are millions of birds creating
Crazy patterns in the sky?
But if that was a group of humans, it would be chaos.
Narrator: And if cheetahs are the worlds
Fastest land animals...
Everything about these animals is built for speed.
Narrator: ...How come they some time give up the chase?
What the heck is going on?
Nature is awe inspiring,
But sometimes it just doesn't make sense.
I have never seen anything like this.
Our team of experts investigates the weirdest animal behavior.
It's amazing.
Narrator: And a most unexpected events...
What is causing that?
Narrator: ...Ever caught on camera.
Man: My god.
Narrator: These are...
August 2017.
Ishaqbini hirola conservancy, kenya.
Rangers come across an unusual sight.
A giraffe and her calf but neither have any
Of their signature markings.
Baker: Well, this clip is phenomenal,
I mean to see a pure white version
Of anything that shouldn't be white
Is always incredible.
Midcap: So this isn't just a giraffe with faded
Coat coloration, this thing is white.
Tall, beautiful, looks like it's in perfect health.
It really does look like a mythical creature,
Where did this come from?
Narrator: To find out what's going on,
We need to know more about the regular giraffes
We're used to seeing.
Burke: Giraffes are famous for being these long=necked,
Long-legged, graceful animals.
And more than anything their pattern as well,
Is very, very distinctive.
Narrator: Giraffe species have varied markings
But the reason for these patterns
Has been puzzling scientists for some time.
Burke: The darker patches actually have more blood vessels
Than the lighter patches.
And we think this might have something to do
With dissipating heat.
But it could also have to do with releasing pheromones
As well to attract mates for example.
But there's other theories
That the reticulated pattern breaks up
The outline of the animal, it just breaks up
Any lines and possibly works as camouflage.
Narrator: As with other animal patterns
It's slightly a combination of all these things
That give the giraffe their unique markings.
But how is it these ones have no color at all?
Midcap: Could it be that this giraffe is albino?
Albinism is a condition where one or more traits
Are handed down to an animal that prevents melanin
From being produced in the organs.
Narrator: Melanin is the pigment that gives skin,
Hair, and eyes their color
But with albinism hair and skin is white
And the eyes are pink as the blood vessels in the iris
Have no pigment to mask them.
So the coat of a giraffe would depend on the production
Of melanin if you were to see all
Those beautiful colorations
But in this case there aren't any.
Albino creatures can be found
Across a vast spectrum of the animal kingdom.
From white moose,
To white wallabys,
To white barracuda.
So it's quite prevalent, although it is
A fairly rare condition, it does affect the majority
Of the animal kingdom.
So I guess the simply conclusion would be,
Oh, it's an albino giraffe, isn't that exciting,
End of story.
But actually if you look closely, this giraffe
Doesn't have the pink eyes, it actually has dark eyes,
So it's not an albino.
Narrator: An albino giraffe is ruled out
So what else could have created this ghostly giant?
Burke: There's another explanation as to why
This white giraffe exists,
And it's a skin disorder called vitiligo.
And it's a condition whereby over time,
The skin is unable to produce melanin.
Narrator: With vitiligo the bodies immune system
Attack it's own melanin cells by mistake,
Gradually creating white skin.
Midcap: It is very rare in the human population,
Only about 1% to 2% of humans have this.
But in the animal kingdom it's even more rare.
Narrator: Rare, yes,
But it has been seen in giraffes before.
A giraffe that was filmed in sunburu in kenya
Had this skin disorder, vitiligo.
Midcap: So could it be possible that this giraffe
Also has vitiligo just like it's kenyan cousin?
Narrator: Her offspring's white coat makes it unlikely.
If it was vitiligo you would expect that youngster
To start off normal and get slowly paler.
Narrator: The fact that this young calf is white
Just like it's mother, rules out vitiligo.
But if the giraffes are not albino
And don't have vitiligo, what is the reason
For their white color?
There's only one real thing that it could be
That's left and it's a beautiful and striking thing
When it happens, but it is incredibly rare,
Which is leucism.
So what you've got here is a leucistic individual.
Narrator: Leucism is a genetic condition
Where animals are born with the loss of some
But not all pigment.
Eyes and hair can still have color,
But the skin is often very pale.
The condition effects as few as one in a thousand
And when you do see these animals,
They are unmistakable.
I've seen it in deer population, near where I live.
A lot of zoos famously have white tigers,
Those are leucistic tigers.
And they're still rare and it still produces
The most peculiarly beautiful mutations.
Narrator: Zoos often adopt leucistic animals
As being without pigment means their chances
Of survival in the wild are pretty slim.
Imagine being a white bird in a wood full of sparrow hawks
You're gonna stand out,
You're gonna be the target number one.
Narrator: But coloration isn't only used for camouflage.
Burke: Pigments have multiple functions,
The pigments will sometimes impress mates
But really fundamentally pigments also help
To protect from uv radiation from the sun.
So albino snakes for example, they don't fare very well,
Partly because they can't thermo regulate,
But partly because they're really exposed to uv radiation.
Any animal that relies on pigmentation
Is quite unusual for them to survive into adulthood.
Narrator: So this sighting of white giraffes
Is particularly special.
Midcap: White giraffes are exceedingly rare.
We don't know how many exist in the wild
And this is only the second one ever spotted
In this national park.
So that's the real magic in this footage
Is not only has this animal survived,
It's actually got offspring as well, so it's managed
To successfully breed.
Narrator: While the deck may be stacked against this
Beautiful and unusual pair of giraffes,
So far, they're beating the odds.
Burke: For now at least, this female and her calf
Are doing really really well.
♪
Narrator: The oxfordshire countryside, uk,
February 2016.
Tens of thousands of starlings have flocked together
And are flying in elegant patterns.
Nelson: Its like a symphony in the sky.
It's almost like flowing water.
It's unlike anything that you've seen before.
Aryee: Oh, that's cool.
It does look like one entity, one organism.
I've always amazed at how intricate and how much
Of a dance a murmuration really is.
I absolutely love them.
Narrator: Murmurations, the term used
To describe this phenomenon,
Are seen all over the world.
But we still don't know the bigger question
Which is why?
Narrator: Around the world, bird watchers are capturing footage
Of murmurations, the gatherings of immense numbers
Of starlings that fly in intricate patterns in the sky.
So the question remains, why do starlings
Murmurate in the first place?
Narrator: To unravel the mystery of murmurations,
We need to figure out how so many birds
Up to six million, can move together.
If that was a group of humans it would be chaos.
Narrator: But it's one starling mirroring the movements
Of the surrounding birds
That keeps the murmuration on course.
All you have to do is keep track of who's in front of you
Who's to your right, who's to your left,
Maybe who's above you.
And if those seven individuals are coordinated
The whole group moves in unison.
It's fascinating.
♪
Narrator: And that's not all,
The staggering speed with which they respond to each other
Has also only recently been discovered.
Aryee: A team in rome found that starlings are able to respond
To the movement of another starling next to it
Within a hundred milliseconds, so that quickly.
Nelson: So now we know the intricacies of a murmuration,
But we still don't know the bigger question,
Which is why are so many birds doing this formation?
Narrator: One clue might be the fact that we often
See these formations at dusk, when the temperatures drop.
♪
Daly: So some researchers believe that murmurations
Are a signal to other birds so they can all gather
In bigger numbers and be warmer.
Aryee: Temperature to me seems like a very plausible reason.
You know, if you're a tiny bird, you want to recruit
Loads of other starlings to come and roost with you,
So you can share that body heat.
Narrator: But murmurations happen
At all times of the year,
Putting the temperature theory in doubt.
Nelson: The problem is that it's not that they're murmurating
Only on cold days,
They're actually murmurating more on warmer days.
So it makes sense that they're not necessarily
Communicating, hey, it's cold, join their group.
But maybe they are communicating something else.
Narrator: Could this instead be a sophisticated way
Of spreading a message through the flock?
Nelson: If you've ever stopped and looked at one
Of these murmurations, you would also hear it,
It's very loud.
[ birds chirping ]
So potentially, they're tweeting to each other
Where the food is.
Aryee: We see this behavior in the blue footed booty,
You have a leader as it were,
That let's out a loud squawk and that then signals
To the other blue footed boobies
That it's time to feast,
And they all dive simultaneously into the water.
♪
It's thought that this increases the chances
That each bird is gonna catch a fish.
♪
Narrator: But for starlings, sharing food information
On such a massive scale just doesn't add up.
Nelson: In a group this size, if you found food,
You might not want the entire group to know
Where it was.
I mean, we're talking thousands and thousands of birds
Because then you'd be out of food.
Narrator: Communication is ruled out,
So what is the reason starlings murmurate?
Daly: When we analyze a starling murmuration
There's often one thing that's fairly evident,
That's the presence of a predator.
Narrator: For years, scientists have been trying to get
To the bottom of why starlings murmurate.
They then noticed the gatherings of these starlings
Often had one thing in common -- a bird of prey.
So are the starlings murmurating to avoid predators.
Narrator: To find out, we visited anne goodenough,
A biologist who's been studying starlings for years.
To ask her if predators could be the cause.
There's a link between size of the murmuration
And the number of predators present and their activity.
We found that when you got predators that were flying in
And around the flock you tended to get bigger murmurations
And the birds stayed up a lot longer.
Narrator: Anne thinks murmurations are likely to be
A strategy that starlings use against predators
Like falcons, eagles, and hawks.
Goodenough: So when a predator flies into a starling flock,
It will try and get focus lock on one specific individual
And go in after that one specific individual,
Exactly in the way that a targeted missile would work.
If that individual is part of a swirling 3d mass,
It's much more difficult to get and maintain focus lock
And ultimately hunt successfully.
Narrator: Footage of a predator attacking the murmuration
Show this defensive technique in action.
Goodenough: That looks like a peregrine falcon,
And you can see that as it's diving in and through the flock
The birds are reacting to it's presence.
The birds are repelling away from that,
Just like iron fillings when they're exposed
To the wrong end of a magnet.
And this is one of those key ideas for why
Murmurations occur in the first place.
And actually this falcon isn't doing terribly well,
It's flying in and through the flock,
But it's actually not being successful
In catching it's dinner.
Aryee: For these starlings are gathering
In these huge murmurations,
They are trying to deliberately confuse
A potential predator and this is called
Predator confusion theory.
Narrator: But during murmurations,
It's not just predator confusion that's at play,
The sheer numbers involved in it
Means the starlings are also employing
What scientists call, the dilution effect.
The dilution effect, essentially is safety in numbers.
Nelson: It's simple math.
If you're one lone individual,
And you see a predator, you're chances are pretty high
That you're gonna get chomped.
But if there's a thousand more of ya out there,
You decrease your chances by a thousand.
Narrator: So for starlings, a murmuration
Isn't just a dance in the sky,
It's an effective aid in survival.
♪
August 7, 2015, hwange national park, zimbabwe.
A tourist is recording his safari adventure,
When his tracker spots a hunt in progress.
And the hunter isn't just any predator,
It's the cheetah, the fastest land animal on the planet.
♪
This cat goes from zero to 60 miles and hour
In just three seconds.
Burke: Everything about these animals are built for speed,
They have this lightweight skeleton,
Really long legs,
Which allows them to take these huge strides.
They even have a specialized inner ear canal,
Which helps to keep their head completely fixed
On their prey.
And then a really long tail which acts like a rudder.
Galante: Cheetah have incredible flexibility
That allow them to pivot on a dime and they can withstand
G forces that would break a human beings leg.
Narrator: Their prey doesn't stand a chance.
But hang on a second, the cheetah's given up.
Why?
Cheetahs often throw in the towel
Even when it seems their prey is in range.
Burke: So with all these incredible adaptations
Begs the question, why are only 58%
Of their hunts successful.
How is that possible?
Narrator: Footage shows that the cheetah,
The world's fastest land animal, giving up the chase.
Again and again
And again.
Why do they give up so often?
Burke: Are they easily distracted?
Narrator: Mother cheetahs usually have three
Or four major distractions, their cubs.
Cheetah cubs are at great risk from lions, leopards,
And hyenas, especially when their mothers
Leave them to hunt.
Galante: A mother cheetah is particularly stressed,
Because only 40% of cubs make it to adulthood
In the kalahari and 5% percent in the sahara.
Daly: So all cheetahs abandoning the hunt
Because of having to be alert
And be on the look-out for predators
In order for them to keep their cubs safe?
Narrator: There is one problem with this idea,
Male cheetahs also give up the chase
And they don't play a role in caring for cubs.
So could it instead be physical stress,
That causes the cheetahs to burn out.
In an effort to avoid competition
From other predators,
Cheetahs hunt during the daytime
When other big cats are sleeping.
However, this can make hunting even more exhausting.
Burke: One of the downsides of hunting in the middle
Of the day is that it's also the hottest part of the day.
Once they decide to give chase,
They only have a limited amount of time
Before their bodies start to overheat.
Narrator: In polokwane, south africa
Dr. Robyn hetem, who studies cheetahs living in sanctuaries,
Put the overheating theory to the test
Using the latest heat monitoring technology.
Hetem: We were able to attach small biologging devices
Which could remotely assess body temperature
Off free-living cheetah in real hunting experiences.
♪
Narrator: So what did she discover?
Hetem: Surprisingly we found no temperature increase
When cheetah were hunting.
The cat is able to dissipate that heat effectively
Through evaporative cooling.
Narrator: Overheating is ruled out,
So what is causing cheetahs to give up the chase?
Professor alan wilson from the royal veterinary college
In the uk analyzes the footage,
He reveals that its he direction of the chase
That can foil cheetahs.
Hunts don't happen in a straight line,
It involves turning, it involves ducking and diving
As the antelope tries to escape and the cheetah tries
To follow those movements.
Very rarely do cheetahs even approach half their top speed
Hunting, it's not about absolute speed,
It's about maneuverability.
Narrator: And it's the zig-zagging course
That prey, such as antelope, go on
That sometimes gives them the upper hand.
Wilson: This is because the antelope defines the hunt
By setting course that is challenging
For the cheetah to follow.
And that is where the antelope gains it's advantage.
Narrator: Meaning cheetahs don't just need speed,
They need agility to get a meal.
When a cheetah is hunting prey, it's the first one
To make a mistake that loses.
The cheetah makes a mistake, the prey is going to win.
Narrator: So, while cheetahs remain the fastest land animals
On the planet, sometimes even they have to admit defeat.
-- Captions by vitac -- www.Vitac.Com
Captions paid for by discovery communications