A jungle within Tokyo? It may come as a surprise that many wild animals, including deer, boar and badgers live right near humans in the Tama River. Improved flood control and regular maintenance have resulted in a range of environments, such as grasslands, woods and exposed rocky and sandy bars extending several hundred meters in all directions. Motion-activated cameras set up along the riverside and animal trails revealed a host of surprises, including a weasel family's hidden fishing spot!

In 2019 a strong typhoon devastated parts of Japan. Viewers of the Darwin program wrote to us expressing concern for the wildlife we profiled in an earlier episode inhabiting the banks of Tokyo's Tama River. Can the "Tamazon" ecosystem still support the deer, boar, badgers and weasels? Our cameras indeed revealed unparalleled destruction ... but also rejuvenation. Waterways have changed course. Sandbars have shifted. And the wildlife? Though challenges remain, the footage paints a rosy future.

The male Japanese stream frog sports some surprising sumo and wrestling moves. But watch this Prince Charming's way with the ladies. During mating season, he'll clutch a female in a vice-like grip and ride piggyback as she makes her way toward the spawning grounds. But it's no pleasure cruise. The long river route is full of fast-flowing rocky turns and waterfalls. No matter the hazard, he will not let go. But a new threat awaits: the bevy of anxious bachelors who don't accept no for an answer!