The Cave of Swallows in Mexico is a 400m vertical shaft, deep enough to engulf the Empire State Building. The Lechuguilla cave system in the USA is 193km long and 500m deep with astonishing crystal formations hanging from its chambers. Although often overlooked, caves are remarkable habitats with equally bizarre wildlife. Cave angel fish cling to the walls behind cave waterfalls with microscopic hooks on their flattened fins. Cave swiftlets navigate by echo-location and build nests out of saliva. The Texas cave salamander has neither eyes nor pigment. Unique access to a hidden world of stalactites, stalagmites, snotites and troglodytes brings a wealth of surprises.
Africa - home to the greatest wildlife gatherings on Earth, but even in this land of plenty, wildlife faces huge challenges. In the jungles, young chimps learn to use tools to find food. On the savannah, a group of cheetah brothers team up to hunt prey twice their size. And, in crystal clear freshwater lakes, caring fish mothers are tricked by devious imposters. Africa’s deserts are tough too. In the Namib, hyena make epic treks to find food on the beach, whilst in the Kalahari, the bizarre aardvark digs deep to find a meal. But for much of Africa’s wildlife the greatest threat comes from humans.
Around 30% of the land's surface is desert, the most varied of our ecosystems despite the lack of rain. Unravel the secrets of desert survival and experience the ephemeral nature of this dynamic environment. Watch Saharan sandstorms nearly a mile high and desert rivers that run for a single day. In the Gobi Desert, rare Bactrian camels get moisture from the snow. In the Atacama, guanacos survive by licking dew off cactus spines. In the USA, the brief blooming of Death Valley triggers a plague of locusts 65km wide and 160km long. A unique aerial voyage over the Namibian desert reveals elephants on a long trek for food and desert lions searching for wandering oryx.