Conservationist Rom Whitaker searches for the last of the supersize crocodiles among the titans of the croc world: Nile crocodiles, saltwater crocodiles, and gharials.

(Premieres Sundays April 4 and April 11) New technologies reveal what's behind incredible "moments of impact" - when animals come into contact with each other and the world around them.

"The Reptiles: Alligators and Crocodiles" looks at the ultimate predators at the margins of the water and the land.