Male giraffes fight neck to neck.
They're battling for the right to mate ...
and to pass on their genes.
The stronger the neck, the better chance of victory.
But whoever loses in this arena might be fed to the lions.
A mature male giraffe tails a female in heat.
Females choose their partners.
She may lead him along for hours before she decides to mate.
But this male doesn't have that much time.
A younger male surveys the scene from a distance.
If he challenges the old bull to a fight, there will be some serious necking.
Not the romantic kind.
The giraffe with the longest and thickest neck has the best chance of winning the battle ...
winning the female ...
and passing on his winning genes.
Some researchers say this trade is an example of sexual selection.
It could be one reason why the giraffe evolved a long neck in the first place.
It's known as the "necks for sex" hypothesis.
There are other theories, too.
Long necks evolved to reach hard-to-get food ...
or for spotting predators on the savannah.
But none of these theories have been proven conclusively.
We do know that male giraffes have weaponized those impressive necks.
A males head and neck combined can weigh up to 140 kilograms.
So, when he swings his head at another male,
it's like wielding a medieval ball and chain.
To top it off,
those horn-like ossicones are capable of stabbing through flesh.
Not all giraffe altercations are violent.
From an early age, males spar with one another to hone their skills
and find their place in the social hierarchy.
In most cases, this behavior circumvents dangerous clashes over mating rights.
This is not one of those cases.
The strong young male moves closer.
He will challenge the old bulls right to mate.
There's an added risk ...
an attentive audience, hungry for a spectacle ....
and perhaps even a giraffe.
The rival is undeterred.
Challenge accepted, the defender leaves the female behind.
He's darker than his opponent.
It's believed that the darker the giraffe, the more dominant he is.
But this younger male may be stronger.
He strikes first.
It's a hit!
And a miss.
The dominant male goes for the flank.
While the young male attacks his opponent's neck.
Two different strategies.
Which one will deliver victory?
Can strength win over experience?
The young challenger is strong.
He's pushing a ton of resistant giraffe flesh, while repeatedly necking.
The old bull keeps pounding the interlopers flank.
He's looking for an opportunity to push him off balance.
Fall, and it will be more than just the end of the battle.
The lions will be in for the kill.
The old male's persistence is paying off.
When he ducks to strike at the flank, his challenger's neck blows don't connect.
The female may not have to wait much longer.
The experienced old male aims to wear the youngster down ...
sap his energy.
The young male's attack strategy is failing.
Now, the lioness embarks on her own tactics.
Nothing the young male throws at him seems to deter the old bull.
And all the while, the lioness creeps closer.
It's over.
The young male concedes defeat.
He made errors that cost him an opportunity to mate.
But his next error may cost him his life.
How much energy is left for the race he needs now to run?
But this giraffe has another tactic ...
Lead the predator into the thick scrub,
where there's no space to launch an attack.
The young male may not have won the right to mate,
but he will survive the day.
While the older, dominant male gets to pass on his winning genes.
Can a lioness bring down a giraffe?
Check out our wildlife battle playlist and you'll find the answer.
Plus many more clever hunting tactics.