O'Shea's Big Adventure

In a rapidly vanishing habitat on Brazil's Atlantic coast, the largest venomous snake in the Americas is on the verge of extinction. During months of drought, the Bushmaster has hidden from sight, and reptile hunter and scientist Mark O'Shea is in a race against the clock to capture the rare and deadly rainforest dweller and extract its venom. But it isn't known as The Ox-Killer for nothing.

The tiny South Atlantic outcrop of Queimada Grande is a Lost World, cut off from the rest of nature. There are no mammals, and to kill birds, the Golden Lancehead has evolved the most powerful venom of any snake in the Americas. Reptile hunter and scientist Mark O'Shea battles his way on to the impregnable island - but then has to face a deadly snake every ten paces.

The Patagonian Lancehead lives further south than any snake in the world. In a vast, windblown wilderness sloping down from the Andes Mountains, the venomous snake's behaviour is still a mystery to science. Reptile hunter and scientist Mark O'Shea heads into Patagonia to track it down, but he's never seen one before, and the Lancehead doesn't like being disturbed.

Mark O'Shea travels to Florida, to investigate a spectacular comeback by nature's great survivor. The crocodiles outlived the dinosaurs, but in the 1970s one species, the American Crocodile, went to the brink of extinction. Now the beast is back, and O'Shea wants to know the secret of its unique recovery - a quest that takes him on a night hunt through the eerie canals of a nuclear power plant.

The swamps of America's Deep South hide a secretive predator from the age of the dinosaurs. Even among the highly specialized killers of the reptile world, the Alligator Snapping Turtle is unique. Unsuspecting prey are deceived by a false worm in its gaping mouth, then ambushed in jaws that can splinter an alligator. But it's also a delicacy, and over-hunting has put the species in danger.

For Mark O'Shea, the Timber Rattlesnake is Nemesis. After a bite from a captive snake, he spent nine days in a hospital, close to death. But the Timber Rattlesnake itself is now in danger. That's where Mark aims to confront the species that nearly killed him, and help the scientists who are trying to save it. But the next bite could be fatal.

The Gila Monster and the Beaded Lizard. The world's only venomous lizards. But can they ever be found together? Do they ever meet? There is one small area in the foothills of Mexico's Sierra Madre mountain range where in theory at least it could happen - the only place on earth where the two species of venomous lizards might be found sharing a canyon.

Baja on the Pacific Coast of Mexico, little known, mysterious - a land of volcanoes and snake infested islands, a land that time forgot. Evolution has been driven by island geography. As part of his quest Mark hopes to get the grabs on a Santa Catalina Island Rattlesnake. It climbs trees to catch birds and has literally evolved out of its rattle, which would scare its prey.

Mark's quest is to find one of the world's rarest and most beautiful frogs, to save it from the threat of extinction and to study its unique toxin for medical research.

Trinidad, the lush tropical island off the west coast of Venezuela, is home to an incredible range of creatures.

The mouth of the largest river in the world boasts an island the size of Switzerland, an island that's not only huge but extremely unusual.

Mark O'Shea returns to his home from home - the jungles of South America - to capture and photograph reptiles in Guyana's Iwokrama rain forest reserve.

Small villages along the Essequibo River deep in the interior of Guyana are being terrorized by one of the world's biggest crocodilians, the Black Caiman. It's one of three most endangered crocodilians in the NewWorld. For Mark, this is his mission. He must journey on the river, face the Caiman and show the villagers how they can live alongside their enemy.