Witnessing clashes over precious resources when the dry season brings a band of gladiators to an African savannah watering hole; a lion-elephant territory brawl, an ant raid on a termite mound and a honey badger's risky dance with a deadly snake.

A look at whether Australian animals' weapons, such as the kangaroo's boxing moves and the redback spider's traps, can help them survive climate change.

Young gladiators earn their stripes in the dense tropical forests of the Americas; a poison dart frog launches a toxic barrage, observe a jaguar-caiman turf war, and see a hungry coati cross paths with a defensive tarantula.

Heading to America's far north for a peek at the ultimate fighters that live along its waterways; a spring thaw kicks off the competition, pitting eagles against herons, bears against bears, and dragonfly nymphs against venomous giant water bugs.