In a river ecosystem in Northern Portugal, we follow Eurasian otter, Kiko, from his first explorations outside his family to his independence as a guardian of his territory.

We delve into dense jungles where humidity dictates all aspects of life; creatures here not only contend with predators and the search for food, but also with diseases that thrive in high moisture.

Tennessee's Great Smoky Mountains live up to their name as America's most popular national park goes up in flames. Meanwhile a mega typhoon pulverises Macao.

Jeremy Wade sets out to discover the true river monster of South America; piranhas get all the press, but is there a more fearsome predator lurking in its rivers?

Gary, Arlie and Damon rescue two gators - one near a restaurant and the other at an industrial equipment supplier - while the team gets Gator Country ready for the busiest day of the year.

Gary searches for a gator in a drainage ditch while Arlie finds another hanging out in a pool, and the Gator Country team trade wrangling for educating as they hit the road for a show in Fort Worth.

In the most arid regions of the planet - where relentless heat dominates day and night - animals face one of nature's greatest challenges: survival in extreme temperatures.

Jeremy is on the trail of a new river monster after a corpse is found with highly unusual injuries. He also uncovers a spate of disappearances and a mysterious creature patrolling the water.

Alaskans pursue scarce resources in anticipation of the coming spring. In Kiwalik, Chip and Agnes Hailstone set up camp for future resource gathering. Andy's trip to his woodpile doesn't go as planned.

The Highlands is a vast landscape dominated by hills, forests and glens; it's a place that's been heavily altered by people and climate, but it's still home to some of Scotland's most iconic species.

An ancient bear cult has survived deep in the Transylvanian forests - here Europe's greatest land predator is a symbol of rebirth, but conflict is unavoidable with ever-increasing numbers.

Alaskans pursue scarce resources in anticipation of the coming spring. In Kiwalik, Chip and Agnes Hailstone set up camp for future resource gathering. Andy's trip to his woodpile doesn't go as planned.

The worst earthquake in almost a century strikes Ecuador. Meanwhile, Indiana suffers one of its worst ever tragedies as a storm blows down the main stage during a festival.

Jeremy is on the trail of a new river monster after a corpse is found with highly unusual injuries. He also uncovers a spate of disappearances and a mysterious creature patrolling the water.

Alaskans pursue scarce resources in anticipation of the coming spring. In Kiwalik, Chip and Agnes Hailstone set up camp for future resource gathering. Andy's trip to his woodpile doesn't go as planned.

The source of the Vltava River lies in the Bohemian Forest; fed by cold and warm Vltava tributaries, Czechia's longest river flows through Sumava moorland and turns dark yellow like liquid gold.

In the most arid regions of the planet - where relentless heat dominates day and night - animals face one of nature's greatest challenges: survival in extreme temperatures.

Hundreds died when the Sobral Santos sank, many allegedly eaten alive. Jeremy retraces the doomed boat's last voyage as he tries to uncover what was behind the Amazon Apocalypse.

On the cusp of springtime, Alaskans encounter unexpected roadblocks in their struggle for survival. Glenn Villeneuve injures his foot while traveling in deep snow.

Hundreds of islands are scattered along Scotland's vast coastline; people have long found a way to live alongside animals here and increase marine protection.

An ancient bear cult has survived deep in the Transylvanian forests - here Europe's greatest land predator is a symbol of rebirth, but conflict is unavoidable with ever-increasing numbers.

On the cusp of springtime, Alaskans encounter unexpected roadblocks in their struggle for survival. Glenn Villeneuve injures his foot while traveling in deep snow.

The worst earthquake in almost a century strikes Ecuador. Meanwhile, Indiana suffers one of its worst ever tragedies as a storm blows down the main stage during a festival.

Hundreds died when the Sobral Santos sank, many allegedly eaten alive. Jeremy retraces the doomed boat's last voyage as he tries to uncover what was behind the Amazon Apocalypse.