Steve Backshall leads a team of elite explorers - including world leading underwater cave explorer Robbie Schmittner, former Royal Marine Aldo Kane and diving camera operator Katy Fraser - into the wilds of the Yucatan Peninsula in Mexico. Under the vast jungle here is the largest unexplored network of caves in the world, comprising thousands of kilometres of passageways. They are stunningly beautiful but incredibly dangerous - much of the system is under water. First the team must trek through tough, scorpion-infested jungle to camp alongside a giant sinkhole in the jungle floor - a dark gateway to an underworld full of nightmarish creatures.
2019 • Nature
Going down into these narrow flooded passageways is not for the faint-hearted but, with only an estimated one percent of the caves explored, it is an opportunity for the team to write themselves into cave diving history, by pushing further in than anyone has before. This is a challenge that tests even the most accomplished cave divers. Steve must face the terrors of being lost in an underwater silt cloud in a cave. But there is a bigger issue at stake. All life in the Yucatan depends on the fresh water in this network of caves, but it's being contaminated by human development. With every metre the team maps, it adds to the knowledge of the system, which, in turns, helps protect it for future generations.
2019 • Nature
Hybrids can be bizarre and they can be deadly. We look at two hybrid animals that owe their existence to human interference - the pizzly bear (a cross between a polar bear and grizzly), which has come into being because of global warming, and the killer bee, brought into existence because of the transfer of African bees to South America.
In three decades, the waters around the remote village of Cabo Pulmo have gone from wildly biodiverse, to barren, to a bountiful and pristine haven for mighty sharks and flying rays once again. See how local fishermen ultimately turned back the clock, restoring one of the world's most majestic coral reefs.
This episode looks at Africa's mountain ranges. From the giant mole rats of the Ethiopian Highlands to the Barbary Macaque monkeys of the Atlas Mountains, this episode gives a fascinating look at the mountains of Africa and the animals that inhabit them.