Learn about crocodile field research in this clip from Gorongosa Park: Rebirth of Paradise. Flying over the north of the park Bob discovers remote rivers choked with enormous crocs. He's never seen so many in his life. He brings in croc experts, Sven Bourquin and Vince Shacks to investigate. But it's not only their numbers they're surprised by but also how they're behaving. It's the beginning of mating season and there should be lots of territorial aggression. But there's not. To figure out what's going on here they need to catch one. They set a trap and on the first night they catch a giant. It's the biggest croc the guys have ever caught. But they need to get it out of the trap to get samples. And that's when the real challenge begins.