A group of lions were marooned in a small island fifteen years ago when the course of the river changed. Instead of perishing, they've learned to swim and became strong (as well as large and smart) enough to hunt the only prey available: the giant buffalo.
Thus, the island has become a unique, ecological experiment. In order to exist without the customary spectrum of weaker African prey like zebra, giraffe and impala, the Duba lions have had to develop distinct strategies in order to trap the single available food source.
They have adapted to this challenge by hunting during the day under the baking African sun, swimming through deep rivers in the hunt for buffalo. This water-based training programme combined with a diet of protein-rich buffalo meat has led to the development of huge muscles, and these super-cats now dwarf other lions.
The island lions also use highly advanced psychology in their quest for food, predicting the course of the buffaloes' daily trek by anticipating their need for water â€” then lying in wait at the precise spot along the river where the herd will eventually stop for refreshment.
In turn, the buffalo have responded to the threat by merging into a vast mega-herd of 1,200 beasts â€” five times the size of a normal group. They have also, at times, turned on the lions, killing isolated cubs.