This is the video which shows the bloody results of a bitter love feud between penguins.
Normally thought of as endearing little birds, penguins can actually fight fiercely if provoked.
Unlike most birds, which have hollow bones in their wings, penguins bones are all solid.
This allows their wings to be used as a ferocious weapon, in which to slap an opponent up to eight times a second.
Penguins’ beaks - normally used to burrow into the ground - can also be used aggressively. In this video, the penguins use them for eye gouging.
The clash, recorded by National Geographic, began as a penguin returned to his burrow to find his mate with another male penguin.
A fight between the two males quickly ensues and they are seen to slap each other viciously and repeatedly.
The aim is for the male to drive off the intruder – but he stands his ground and fights back.
While blubber on the penguins helps protect their vital organs, blood is drawn quickly.
The fight appears to end in a stalemate, as the male penguins call for the female to choose between them.
After she picks the intruding male over her original mate, her former lover continues the attack.
He escalates, using his beak to attack the face and eyes of his opponent, resulting in a large amount of blood to pour from both birds.
However, the female stands by her new mate, rejecting a final appeal from her rejected partner.
