Swimming Lions

Scientists are on the tail of one of nature's best kept secrets. Deep within Africa's untamed wilderness lions are doing the last thing we would've ever expected. They're taking to the water. Dry savannah dominates much of Southern Africa, but sprawling over the northern reaches of Botswana the terrain is startlingly different. There, in the midst of the Kalahari Desert is a surprising world of water where life flourishes.

Every year around 11 billion cubic meters of water pour into the Okavango, most of which arrives as a huge flood in the middle of winter. The waters that flood the Okavango start out as rain falling on the mountains of Angola to the north of Botswana. The water pours into to the vast Okavango River which bursts its banks as it floats south, fanning into the massive flat plains that make up the Okavango delta.

Nowhere else on the planet is there a freshwater delta of this size, landlocked far from the sea. The Okavango is a result of the unusual geology of this area. Around two million years ago there was an ancient freshwater lake there known as Lake Makgadikgadi. It was an enormous inland sea so wide that it would've taken nearly a day to cross it by boat. Over the past 20,000 years, since the end of the last ice age, Lake Makgadikgadi gradually dried up. As the water level dropped a vast network of small rivers and islands emerged, and so the Okavango we recognize today was formed.

Lions have a reputation for taking life in their stride. Arguably the most adaptable of all the big cats they dominate places as diverse as the harshest deserts and lush woodlands. But the Okavango is so extreme that to find lions thrive there is a real surprise. Making it there has involved a dramatic sacrifice. The lions have had to take a plunge into a totally new way of life.

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