The Okavango Delta, a rich mosaic of islands and waterways, hosts many of the same wildlife species that live in Africa's dry savannas.

Elephants and African buffaloes find ample space in the delta's sprawling flood plains, while hippopotamuses lounge in the many lakes and rivers.

As impressive as they are to us, these African giants are far less interesting to lions in the region. It's the slighter herbivores, like zebras and antelopes, which have drawn the great felines to the delta in large numbers.

Blue wildebeests, elands, roan antelopes, impalas, kudus, steenboks and sable antelopes abound in this diverse environment. They keep a steady vigil among the lions, along with common duikers, reedbucks, waterbucks, bushbucks, tsessebes, giraffes and Burchell's zebras.

The delta also supports animals that are rarely seen in the savanna. The most important of these, as far as Okavango lions are concerned, is a semi-aquatic antelope called the red lechwe.

A medium-sized antelope with long, curving horns, the red lechwe is well adapted to its waterlogged existence. Its hooves are elongated with a wide splay, which allows it to traverse over swampy terrain without sinking.

It lives in seasonal swamps and flood plains, where it feeds on grasses and sedges in meadows inundated with water. It will wade up to its belly or shoulders to reach food, foraging up to several miles from shore.

Clumsy and slow on dry land, the red lechwe is incredibly fast in the water, where its elongated hooves help support it on the soft, muddy bottoms. This makes the animal more likely to take to the water to avoid predators than it is to try its luck on land.

The red lechwe makes spectacular leaps when startled, its overdeveloped hindquarters providing added thrust. A group of red lechwe jumping and scattering in different directions can quickly confuse a lion.

This ability to get a quick start and bewilder its attackers, together with its skill in moving swiftly across marshy terrain, makes the red lechwe a particularly difficult quarry for lions.

Lions are on an equal playing field with land-based prey, like wildebeest and impala, but they are at a disadvantage in the water. This semi-aquatic antelope can outpace lions in the water faster than savanna antelopes can on land.

Yet the red lechwe is one of the most important food sources for the lions of the Okavango Delta.

Part of the lions' success in hunting red lechwe can be attributed to the fact that they have plenty of opportunities to do so. The red lechwe is the most abundant large mammal of the Okavango Delta's flood-plain grasslands.

Over the past few thousand years, delta lions have become adapted in subtle, but significant, ways to their watery existence in the Okavango Delta. A savanna lion would likely have less success hunting red lechwe in the water than a lion born and raised in the delta.

The balance tips in the lion's favor when the floodwaters retract after the flood season.

"Some (red lechwe) remain around waterholes when the flood plains dry up," ecologist Christiaan Winterbach said in an interview with Animal Planet Online. This "leaves them fairly vulnerable to predators for that period until the next floodwater arrives, or until they move back to where there's more water available for them."

The fact that lions of the Okavango Delta regularly hunt and kill this semi-aquatic antelope, which their savanna cousins have no experience with, proves how well adapted the big cats have become to this wetland environment.