Millions of years of isolation from the African mainland have meant that Madagascar has a great variety of unique plants and animals. In fact, of the estimated 200,000 species that live on the island, 75 percent occur nowhere else on earth. In the depths of a remote cave system in northern Madagascar, rumors abound about a mysterious population of subterranean crocodiles that could be a new subspecies of the Nile crocodile. Sept. 28, Sunday, 9 p.m. ET
In "Cave Crocs," National Geographic Ultimate Explorer contributing correspondent Dr. Brady Barr travels to Madagascar’s Ankarana Nature Reserve to unravel the mystery of these rare crocodiles. He is joined by Spanish biologist Gerardo Garcia Herrero, cameraman Eric Cochran and local guide Angelin. Together they journey into an underground labyrinth, where more than 60 miles of caves, passages and rivers twist and turn below the park’s plateau. No place for the faint-hearted, the caves are home to blind fish, eels as thick as a man’s thigh, bats, spiders and scorpions. Passages veer off on all sides, and it would be all too easy to get lost in these depths amongst the man-eaters.
How do the crocs navigate in these pitch-black corridors? What do they eat? Have generations of underground living produced a whole new subspecies of crocodile? Before the team can answer these questions, they will have to venture deep into the caves and capture some of them. But will they find the crocs before the crocs find them? Join Barr and his team as they go underground to track what could be the world’s only cave-dwelling crocodiles.