'The great lions of the Tsaro pride are larger, more fearsome and more innovative than your typical lion. These enormous lions have thick necks and heavy chests built to wade through water and hunt places big cats normally avoid. Trapped on an island with these giant killers are thousands of buffalo who are forced to devise defensive tactics and eventually learn to fight back. See the battle unfold from a unique perspective as National Geographic Channel tracks the movements from the air and up close

The rich surroundings and unique environment of the Okavango River Delta have morphed the Tsaro lions into huge, thick-necked beasts. Far more aggressive and dangerous than their cousins on the Serengeti, these lions defy what we thought we knew about big cats. Normally lazy males attack viciously as lionesses wade through water for a better angle on their prey.

But the buffalo are no sitting ducks. As prisoners on an island only five years old, they've developed their own strategies for survival. Relentless Enemies takes you deep into the action as a wall of angry buffalo thwarts a lion attack. Filmed in High Definition, Relentless Enemies watches from the air as competing strategies for attack and defense unfold. Then, get up close as cubs go missing, competitive prides encroach on Tsaro territory and the future of the pride hangs in the balance.

See how the Tsaro lions survive hyenas, internal battles and dangerous prey to become larger and stronger than ever. Could this be the latest evolutionary step of the species? See for yourself as the pack fights for ultimate supremacy on Relentless Enemies.'