Each winter in Zambia, Africa, the dry season saps the land of moisture and sets off a battle for survival. Hippos and crocs guard the shrinking Luangwa River. Lions and leopards plot their attacks on migrating beasts in order to feed their cubs. Standing tall like a beacon of brilliant green in this bleak landscape stands something that defies nature's rhythms: a sausage tree. It's a miracle of Zambia that bears sweet gifts of large fruits and crimson flowers that sustain these wild residents until the unforgiving season ends.

It stands tall in the semi-arid desert of the Kalahari, giving its inhabitants much-needed shade during summer days, large pods when food is scarce, and a foundation for one of the most remarkable constructions built by a colony of birds. It's the camelthorn, one of only a handful of large trees that can take root in the Kalahari's deficient soil. Discover the evolutionary secrets that allow it to tower as a master of survival in the vast expanses of these African plains, where living is an often unthinkable challenge.

There is much more to the African savannas than just predator and prey. Here, some of the most remarkable trees provide its inhabitants with two fundamentals: food and shelter. In the Manyeleti Game Reserve, one tree stands out above all others: the marula. It feeds many herbivores, from the smallest insects and rodents to the largest land mammal on Earth. See the integral role it plays over the dramatically extreme seasons in South Africa, and see why this tree is undeniably a tree of life.