Scientists uncover clues at a fossil dig site in North Dakota that reveal details about the day an asteroid struck Earth and wiped out the dinosaurs.

Sir David Attenborough explores the dangerous frontiers created by the world's coasts, where animals fight for survival amid constant change; there are some unexpected residents on Namibia's Skeleton Coast.

Exploring the worst mass extinction the planet has ever seen, when as much as 90% of all species died 252 million years ago; this moment in Earth's history took life to the brink, wreaking havoc and destruction on an unprecedented scale.

In anticipation of the coming spring, Alaskans pursue scarce resources.

Brian learns about the oldest planet in the solar system Jupiter, which uses its size to manipulate other planets.

Costa Rica is a world of its own; a tropical corridor squeezed between two great oceans, powered by rivers and volcanoes; its volcanoes erupt and deposit minerals into the soil, making the land fertile and creating the country's rich bio-diversity.

In anticipation of the coming spring, Alaskans pursue scarce resources.

When a fawn is found stuck in thick, toxic tar, Hope assembles her entire team to wash and care for it in a desperate bid to save its life.

Iceland is the world's largest volcanic island and new ground is born daily.

Explores strongholds abandoned by their architects; a lost city in the Amazon jungle; a desert fortress made by humanity's most notorious empire; explores a city of identical castles; examines a Greek isle's bloody history from the air.

When a fawn is found stuck in thick, toxic tar, Hope assembles her entire team to wash and care for it in a desperate bid to save its life.

Iceland is the world's largest volcanic island and new ground is born daily.

Explores strongholds abandoned by their architects; a lost city in the Amazon jungle; a desert fortress made by humanity's most notorious empire; explores a city of identical castles; examines a Greek isle's bloody history from the air.

Daybi struggles to make amends as the group tackles a grueling paddle on the open ocean; they once again leave little time to erect a shelter finished before nightfall.

As winter winds down, Alaskans encounter roadblocks in their struggle for survival.

Brian learns how Saturn began its life as a strange planet of rock and ice, born outside the snow line, with an abundance of building materials.

Daybi struggles to make amends as the group tackles a grueling paddle on the open ocean; they once again leave little time to erect a shelter finished before nightfall.

Asia's jungles are beautiful and exceptionally diverse, but whilst they provide shelter, food, and opportunity, they are also full of dangers and hidden threats.

As winter winds down, Alaskans encounter roadblocks in their struggle for survival.

Scientists uncover clues at a fossil dig site in North Dakota that reveal details about the day an asteroid struck Earth and wiped out the dinosaurs.

Sir David Attenborough explores the dangerous frontiers created by the world's coasts, where animals fight for survival amid constant change; there are some unexpected residents on Namibia's Skeleton Coast.

Exploring the worst mass extinction the planet has ever seen, when as much as 90% of all species died 252 million years ago; this moment in Earth's history took life to the brink, wreaking havoc and destruction on an unprecedented scale.

At the onset of winter, Alaskans combat threats; a storm batters Kavik as Sue fortifies camp; Ricko searches for elusive wildlife; the Hailstones ice fish; Johnny secures food in the Brooks Range.

Tells an intimate and enchanting story of an emperor penguin chick's first precarious months on the ice, growing up in the world's most extreme nursery.

Gordon Buchanan begins training the cubs for their new life in the wilderness; with just ten weeks left before release, little Pasha is still struggling.

At the onset of winter, Alaskans combat threats; a storm batters Kavik as Sue fortifies camp; Ricko searches for elusive wildlife; the Hailstones ice fish; Johnny secures food in the Brooks Range.

Tells an intimate and enchanting story of an emperor penguin chick's first precarious months on the ice, growing up in the world's most extreme nursery.

The trio heads to South Africa where they encounter the great white shark.

As winter winds down, Alaskans encounter roadblocks in their struggle for survival.

Brian learns how Saturn began its life as a strange planet of rock and ice, born outside the snow line, with an abundance of building materials.

Iceland is the world's largest volcanic island and new ground is born daily.

As winter winds down, Alaskans encounter roadblocks in their struggle for survival.

Hope realizes she's not prepared to rescue animals from an oil spill, so she heads across the continent to learn from the best before disaster strikes.

Iceland's volcanoes generate one third of earth's land-based lava, but the land was sculpted by ice.

Peek at landmarks in places where they shouldn't be; wing your way over an imperial pyramid in the Netherlands, a metal sphere in remote Russia, a lion shape carved into an English hillside and a bare swath cut through an Austrian forest.

Hope realizes she's not prepared to rescue animals from an oil spill, so she heads across the continent to learn from the best before disaster strikes.

Iceland's volcanoes generate one third of earth's land-based lava, but the land was sculpted by ice.

Peek at landmarks in places where they shouldn't be; wing your way over an imperial pyramid in the Netherlands, a metal sphere in remote Russia, a lion shape carved into an English hillside and a bare swath cut through an Austrian forest.

Everyone is left shocked after an adventurer calls it quits and leaves the journey for good; the remaining five are torn apart, as some look to potentially branch off on their own.

As winter comes to a close, there are no shortcuts for Alaskans as they wrap up the season.

Professor Brian Cox journeys to the remotest part of the solar system where the mysteries of Saturn, Uranus and Neptune remain in the shadows.

Everyone is left shocked after an adventurer calls it quits and leaves the journey for good; the remaining five are torn apart, as some look to potentially branch off on their own.

In the planet's most densely populated continent, animals live at extremely close quarters with people, from tigers making a home in town to elephants stopping traffic for food.

As winter comes to a close, there are no shortcuts for Alaskans as they wrap up the season.

At the onset of winter, Alaskans combat threats; a storm batters Kavik as Sue fortifies camp; Ricko searches for elusive wildlife; the Hailstones ice fish; Johnny secures food in the Brooks Range.

Tells an intimate and enchanting story of an emperor penguin chick's first precarious months on the ice, growing up in the world's most extreme nursery.

Levison and Alberto travel through Guatemala, Honduras and Nicaragua.

Brian examines the universal laws of nature; planet size can make a difference between life and death.

There are not five separate oceans, but one; its waters linked by powerful forces that keep them on the move.

The same 92 elements that exist on Earth can be found throughout the cosmos.

Brian examines the universal laws of nature; planet size can make a difference between life and death.

There are not five separate oceans, but one; its waters linked by powerful forces that keep them on the move.

The same 92 elements that exist on Earth can be found throughout the cosmos.

As winter comes to a close, there are no shortcuts for Alaskans as they wrap up the season.

Professor Brian Cox journeys to the remotest part of the solar system where the mysteries of Saturn, Uranus and Neptune remain in the shadows.

Iceland's volcanoes generate one third of earth's land-based lava, but the land was sculpted by ice.

As winter comes to a close, there are no shortcuts for Alaskans as they wrap up the season.

Twin fawns arrive at the centre; a volunteer searches for orphans in the woods; Hope tends to a tiny owl.

A perfect circle carved around an ancient peak; a scary phenomenon in the Pacific; strange shapes in a Middle Eastern desert; a formation below the ocean's surface.

A journey down one of the wild rivers in the world, the Yukon; the unusual trip starts in an aircraft piloted by a painter and the odyssey ends with a visit to a graveyard of disintegrating rear-wheel steamers.

Costa Rica is a world of its own; a tropical corridor squeezed between two great oceans, powered by rivers and volcanoes; its volcanoes erupt and deposit minerals into the soil, making the land fertile and creating the country's rich bio-diversity.

Zoom in on some otherworldly sights; spot a giant glacier on the Red Planet, let the milky seas off the coast of Java bathe your vision, ponder a huge hexagon floating above Saturn and take a spin around a doughnut-shaped lake in Saskatchewan.

A journey down one of the wild rivers in the world, the Yukon; the unusual trip starts in an aircraft piloted by a painter and the odyssey ends with a visit to a graveyard of disintegrating rear-wheel steamers.

When a fawn is found stuck in thick, toxic tar, Hope assembles her entire team to wash and care for it in a desperate bid to save its life.

In the remote reaches of Asia's frozen north, creatures must overcome unique challenges, finding exceptional ways to thrive in a hostile world that pushes life to its very limits.

Asia's jungles are beautiful and exceptionally diverse, but whilst they provide shelter, food, and opportunity, they are also full of dangers and hidden threats.

In the planet's most densely populated continent, animals live at extremely close quarters with people, from tigers making a home in town to elephants stopping traffic for food.

Scientists uncover clues at a fossil dig site in North Dakota that reveal details about the day an asteroid struck Earth and wiped out the dinosaurs.

Sir David Attenborough explores the dangerous frontiers created by the world's coasts, where animals fight for survival amid constant change; there are some unexpected residents on Namibia's Skeleton Coast.

Exploring the worst mass extinction the planet has ever seen, when as much as 90% of all species died 252 million years ago; this moment in Earth's history took life to the brink, wreaking havoc and destruction on an unprecedented scale.

Tells an intimate and enchanting story of an emperor penguin chick's first precarious months on the ice, growing up in the world's most extreme nursery.

More than any other continent, North America is defined by extreme weather and seasonal change; for animals that live here this poses great challenges, but for those with a pioneering spirit it can also offer great rewards.

Brian takes a fresh look at the astonishing concept of gravity.

Setting out on an odyssey across the Indian Ocean to see whether the hunters are adapting to the rapidly changing planet; traveling from the coast of South Africa to the Maldives, coming face-to-face with oceanic blacktip sharks.

More than any other continent, North America is defined by extreme weather and seasonal change; for animals that live here this poses great challenges, but for those with a pioneering spirit it can also offer great rewards.

Brian takes a fresh look at the astonishing concept of gravity.

Setting out on an odyssey across the Indian Ocean to see whether the hunters are adapting to the rapidly changing planet; traveling from the coast of South Africa to the Maldives, coming face-to-face with oceanic blacktip sharks.

More than any other continent, North America is defined by extreme weather and seasonal change; for animals that live here this poses great challenges, but for those with a pioneering spirit it can also offer great rewards.

Brian takes a fresh look at the astonishing concept of gravity.

Setting out on an odyssey across the Indian Ocean to see whether the hunters are adapting to the rapidly changing planet; traveling from the coast of South Africa to the Maldives, coming face-to-face with oceanic blacktip sharks.

The same 92 elements that exist on Earth can be found throughout the cosmos.

Lynn plays surrogate to baby beavers; Zach is forced to follow a seal along the coastline; a patient returns after a release goes wrong.

Decoding the secrets of long-lost human settlements; scrutinizing a mysterious Norwegian mound, a prehistoric stone circle on the banks of the Tagus River, a lost city in the cradle of civilization and bizarre rock shapes.

Meandering through the black waters of a primordial river immortalized in a folk song.

Iceland is the world's largest volcanic island and new ground is born daily.

Explores strongholds abandoned by their architects; a lost city in the Amazon jungle; a desert fortress made by humanity's most notorious empire; explores a city of identical castles; examines a Greek isle's bloody history from the air.

Meandering through the black waters of a primordial river immortalized in a folk song.

Hope realizes she's not prepared to rescue animals from an oil spill, so she heads across the continent to learn from the best before disaster strikes.

Scientists uncover clues at a fossil dig site in North Dakota that reveal details about the day an asteroid struck Earth and wiped out the dinosaurs.

Sir David Attenborough explores the dangerous frontiers created by the world's coasts, where animals fight for survival amid constant change; there are some unexpected residents on Namibia's Skeleton Coast.

Exploring the worst mass extinction the planet has ever seen, when as much as 90% of all species died 252 million years ago; this moment in Earth's history took life to the brink, wreaking havoc and destruction on an unprecedented scale.

Steve Backshall is in Australia, searching for the world's most freaky and venomous fish: the stonefish; he also finds trapdoor spiders and a snake that hunts bats.

A race to find the planet's 60 deadliest creatures.

Levison and Alberto travel through Guatemala, Honduras and Nicaragua.

Levison and Alberto visit the landscapes, colonial cities, active volcanoes and mountains of Nicaragua and Costa Rica.

An orphaned baby Triceratops must outwit a deadly Tyrannosaurus rex.

Exploring fossils from a North Dakota site that may reveal what happened when an asteroid struck Earth and wiped out the dinosaurs.

Exploring the evolutionary path of the Tyrannosaurus rex; following the journey of two dinosaur brothers and the theoretical evolution from smaller dinosaurs originating in Asia based on fossil findings in China.

An orphaned baby Triceratops must outwit a deadly Tyrannosaurus rex.

Exploring fossils from a North Dakota site that may reveal what happened when an asteroid struck Earth and wiped out the dinosaurs.

Exploring the evolutionary path of the Tyrannosaurus rex; following the journey of two dinosaur brothers and the theoretical evolution from smaller dinosaurs originating in Asia based on fossil findings in China.

Asia has the longest coastline of any continent, rich coral reefs, and never-seen-before animal behavior; exploring Asia's diverse waters.

Asia is the most mountainous continent on earth; from the tropical south to its barren centre, its highest places are home to some of our planet's most remarkable wildlife.

In the remote reaches of Asia's frozen north, creatures must overcome unique challenges, finding exceptional ways to thrive in a hostile world that pushes life to its very limits.

Asia's jungles are beautiful and exceptionally diverse, but whilst they provide shelter, food, and opportunity, they are also full of dangers and hidden threats.

In the planet's most densely populated continent, animals live at extremely close quarters with people, from tigers making a home in town to elephants stopping traffic for food.

A cow winds up at Hope For Wildlife; the spring orphans are all grown up, and Hope has to decide who's ready for release.

The highest tides in the world are found in the Bay of Fundy on Canada's east coast.

Examine strange relics forgotten by time; visit a perturbing circle of stone in the Golan Heights; a mountain of headless statues in Turkey; a castle left to crumble in the Saudi Arabian desert; a time-worn secret in the wilds of Peru.

A cow winds up at Hope For Wildlife; the spring orphans are all grown up, and Hope has to decide who's ready for release.

The highest tides in the world are found in the Bay of Fundy on Canada's east coast.

Examine strange relics forgotten by time; visit a perturbing circle of stone in the Golan Heights; a mountain of headless statues in Turkey; a castle left to crumble in the Saudi Arabian desert; a time-worn secret in the wilds of Peru.

A cow winds up at Hope For Wildlife; the spring orphans are all grown up, and Hope has to decide who's ready for release.

Alaskans enter a new dawn in the Arctic winter.

Satellites follow an elephant family struggling through drought; reveals previously unknown emperor penguin colonies from the color of their poo; discovers mysterious ice rings that could put seal pups in danger.

In the heart of Asia lie vast arid lands; these deserts and dry grasslands are so hostile, they push life to the limit; the animals that live here are some of the toughest on earth - they are Asia's great survivors.

Alaskans enter a new dawn in the Arctic winter.

Alaskans enter a new dawn in the Arctic winter.

Satellites follow an elephant family struggling through drought; reveals previously unknown emperor penguin colonies from the color of their poo; discovers mysterious ice rings that could put seal pups in danger.

In the heart of Asia lie vast arid lands; these deserts and dry grasslands are so hostile, they push life to the limit; the animals that live here are some of the toughest on earth - they are Asia's great survivors.

Levison and Alberto explore a vampire bat-infested cave, the Panama Canal and modern Panama City.

Levison begins his journey in Afghanistan's remote and inhospitable Wakhan Corridor.

A Spinosaurus, the world's largest ever predatory dinosaur, struggles to bring up his babies and lead his young family across one of the deadliest environments on Earth.

Levison and Alberto explore a vampire bat-infested cave, the Panama Canal and modern Panama City.

Levison begins his journey in Afghanistan's remote and inhospitable Wakhan Corridor.

A Spinosaurus, the world's largest ever predatory dinosaur, struggles to bring up his babies and lead his young family across one of the deadliest environments on Earth.

Alaskans enter a new dawn in the Arctic winter.

Satellites follow an elephant family struggling through drought; reveals previously unknown emperor penguin colonies from the color of their poo; discovers mysterious ice rings that could put seal pups in danger.

In the heart of Asia lie vast arid lands; these deserts and dry grasslands are so hostile, they push life to the limit; the animals that live here are some of the toughest on earth - they are Asia's great survivors.

Alaskans enter a new dawn in the Arctic winter.

Hope opens her doors to the public.

Along the west coast of Great Britain, the world's longest uninterrupted footpath forges through more than 800 miles of breathtaking scenery; the diverse landscape of the Welsh coast is a geological treasure.

Confront objects that make no sense; spot a spinning island in an Argentinian marsh, a colossal triangle stuck in the Arizona desert, mysterious multicoloured pools across northern Ethiopia and a huge human figure hidden in the Australian outback.

Hope opens her doors to the public.

Along the west coast of Great Britain, the world's longest uninterrupted footpath forges through more than 800 miles of breathtaking scenery; the diverse landscape of the Welsh coast is a geological treasure.

Confront objects that make no sense; spot a spinning island in an Argentinian marsh, a colossal triangle stuck in the Arizona desert, mysterious multicoloured pools across northern Ethiopia and a huge human figure hidden in the Australian outback.

Hope opens her doors to the public.

Alaska residents labor their way through winter's challenges.

The Australian outback is covered in pale spots, the work of wombats; a clearing in the green canopy of the Congo rainforest has been created by an elephant gathering; the twists and turns of the Amazon make a home for rehabilitated manatees.

Many passionate people are dedicated to saving the wild animals of Asia; these individuals and their ingenious solutions give hope and optimism for the future of the continent.

Alaska residents labor their way through winter's challenges.

Levison and Alberto explore a vampire bat-infested cave, the Panama Canal and modern Panama City.

Levison begins his journey in Afghanistan's remote and inhospitable Wakhan Corridor.

A Spinosaurus, the world's largest ever predatory dinosaur, struggles to bring up his babies and lead his young family across one of the deadliest environments on Earth.

In northern Queensland, nature nerd Dr Ann Jones comes face to face with one of Australia's mightiest predators, the bull shark, and discovers there's much more to them than meets the eye.

A race to find the planet's 60 deadliest creatures.

The boys are in Laos in search of a diabolical catfish, but the best place to find it is near the mouth of Mekong, where it is believed that there is a hidden world. It is a difficult journey and the road is full of evil spirits.

Alaska residents labor their way through winter's challenges.

In northern Queensland, nature nerd Dr Ann Jones comes face to face with one of Australia's mightiest predators, the bull shark, and discovers there's much more to them than meets the eye.

A race to find the planet's 60 deadliest creatures.

The boys are in Laos in search of a diabolical catfish, but the best place to find it is near the mouth of Mekong, where it is believed that there is a hidden world. It is a difficult journey and the road is full of evil spirits.

Along the west coast of Great Britain, the world's longest uninterrupted footpath forges through more than 800 miles of breathtaking scenery; the diverse landscape of the Welsh coast is a geological treasure.

Alaska residents labor their way through winter's challenges.

The Australian outback is covered in pale spots, the work of wombats; a clearing in the green canopy of the Congo rainforest has been created by an elephant gathering; the twists and turns of the Amazon make a home for rehabilitated manatees.

Many passionate people are dedicated to saving the wild animals of Asia; these individuals and their ingenious solutions give hope and optimism for the future of the continent.

Alaska residents labor their way through winter's challenges.

The staff steps up to release the few remaining patients, when Hope suffers a personal tragedy.

Ireland is small in size but epic in wonder; surrounded by the Atlantic ocean, Cliffs of Moher to the extraordinary Giant's Causeway, this land has been shaped and reshaped by both the power of water and violent geological forces.

Take a deep dive into watery enigmas; glide over a sunken Italian city; a unique underwater cemetery in the Florida Keys; a yellow brick road to nowhere in the depths of the North Pacific; puzzling rocky constructions off the coast of Australia.

The staff steps up to release the few remaining patients, when Hope suffers a personal tragedy.

Ireland is small in size but epic in wonder; surrounded by the Atlantic ocean, Cliffs of Moher to the extraordinary Giant's Causeway, this land has been shaped and reshaped by both the power of water and violent geological forces.

Take a deep dive into watery enigmas; glide over a sunken Italian city; a unique underwater cemetery in the Florida Keys; a yellow brick road to nowhere in the depths of the North Pacific; puzzling rocky constructions off the coast of Australia.

The staff steps up to release the few remaining patients, when Hope suffers a personal tragedy.

Alaskans confront the environment and themselves as winter bears down.

From space, satellite cameras reveal that Earth is a kaleidoscope of color; turquoise plankton blooms trigger a feeding frenzy, China turns yellow with rapeseed flowers, and mysterious green lights appear in the ocean.

A group of chimps in Senegal is led by an alpha male named Dave.

Alaskans confront the environment and themselves as winter bears down.

In northern Queensland, nature nerd Dr Ann Jones comes face to face with one of Australia's mightiest predators, the bull shark, and discovers there's much more to them than meets the eye.

A race to find the planet's 60 deadliest creatures.

The boys are in Laos in search of a diabolical catfish, but the best place to find it is near the mouth of Mekong, where it is believed that there is a hidden world. It is a difficult journey and the road is full of evil spirits.

Exploring fossils from a North Dakota site that may reveal what happened when an asteroid struck Earth and wiped out the dinosaurs.

Australia was once home to a group of animals known as megafauna, giants who lived here for millions of years; in a blink of time, the megafauna disappeared forever; a team of scientists are reopening this paleolithic cold case.

Sir David Attenborough reveals new animal behaviors in the ocean.

Earth's journey into the deep freeze starts with fire over 800 million years ago; Long before the age of the dinosaurs, before there was even animal life, the supercontinent Rodinia breaks up.

Australia was once home to a group of animals known as megafauna, giants who lived here for millions of years; in a blink of time, the megafauna disappeared forever; a team of scientists are reopening this paleolithic cold case.

Sir David Attenborough reveals new animal behaviors in the ocean.

Earth's journey into the deep freeze starts with fire over 800 million years ago; Long before the age of the dinosaurs, before there was even animal life, the supercontinent Rodinia breaks up.

Alaskans confront the environment and themselves as winter bears down.

From space, satellite cameras reveal that Earth is a kaleidoscope of color; turquoise plankton blooms trigger a feeding frenzy, China turns yellow with rapeseed flowers, and mysterious green lights appear in the ocean.

A group of chimps in Senegal is led by an alpha male named Dave.

Alaskans confront the environment and themselves as winter bears down.

The rehab is flooded with orphaned seals, with some frozen solid in ice.

From the icy peaks of age-old mountain glaciers to the fog-shrouded canopies of Canada's only rainforest, it's the wettest place in North America.

Psychedelic swirls in the Utah wastelands; a bizarre configuration of circles in the Sahara; hidden lines with the help of a drone; a remote polka-dot lake in Canada.

The rehab is flooded with orphaned seals, with some frozen solid in ice.

From the icy peaks of age-old mountain glaciers to the fog-shrouded canopies of Canada's only rainforest, it's the wettest place in North America.

Psychedelic swirls in the Utah wastelands; a bizarre configuration of circles in the Sahara; hidden lines with the help of a drone; a remote polka-dot lake in Canada.

The rehab is flooded with orphaned seals, with some frozen solid in ice.

Alaskans rediscover old practices to get through the heart of winter.

The Earth's surface is changing faster than ever in human history: cities grow, forests disappear and glaciers melt; a man feeds thousands of parakeets in a city; in Sumatra, a female orangutan and her daughter face life in a forest under threat.

A colony of emperor penguins arrive in Atka Bay, after three months at sea, to raise their chicks through the coming winter.

Alaskans rediscover old practices to get through the heart of winter.

Australia was once home to a group of animals known as megafauna, giants who lived here for millions of years; in a blink of time, the megafauna disappeared forever; a team of scientists are reopening this paleolithic cold case.

Sir David Attenborough reveals new animal behaviors in the ocean.

Earth's journey into the deep freeze starts with fire over 800 million years ago; Long before the age of the dinosaurs, before there was even animal life, the supercontinent Rodinia breaks up.

The winter season grows more erratic, and Alaskans are forced to adapt.

The extraordinary story of how the human species, Homo sapiens, first emerged, where the discoveries of recent years are revolutionising the understanding of humanity's origin story.

Exploring fossils from a North Dakota site that may reveal what happened when an asteroid struck Earth and wiped out the dinosaurs.

The winter season grows more erratic, and Alaskans are forced to adapt.

The extraordinary story of how the human species, Homo sapiens, first emerged, where the discoveries of recent years are revolutionising the understanding of humanity's origin story.

The boys are in Laos in search of a diabolical catfish, but the best place to find it is near the mouth of Mekong, where it is believed that there is a hidden world. It is a difficult journey and the road is full of evil spirits.

Alaskans rediscover old practices to get through the heart of winter.

The Earth's surface is changing faster than ever in human history: cities grow, forests disappear and glaciers melt; a man feeds thousands of parakeets in a city; in Sumatra, a female orangutan and her daughter face life in a forest under threat.

A colony of emperor penguins arrive in Atka Bay, after three months at sea, to raise their chicks through the coming winter.

Alaskans rediscover old practices to get through the heart of winter.

Hope puts everything on the line to save an orphaned black bear cub; two bobcats are ready for release, but they won't go easy.

The jungle, underwater caves and lush everglades of the Yucatan shelter Mexico's largest predator, Morelet's crocodile.

Learning why an important urban center is sinking toward oblivion; soaring over sprawling ruins buried under Saharan sands; learning the modern secret of an ancient fortress; eyeing a ghost town on the edge of the Gobi.

Hope puts everything on the line to save an orphaned black bear cub; two bobcats are ready for release, but they won't go easy.

The jungle, underwater caves and lush everglades of the Yucatan shelter Mexico's largest predator, Morelet's crocodile.

Learning why an important urban center is sinking toward oblivion; soaring over sprawling ruins buried under Saharan sands; learning the modern secret of an ancient fortress; eyeing a ghost town on the edge of the Gobi.

Hope puts everything on the line to save an orphaned black bear cub; two bobcats are ready for release, but they won't go easy.

Alaskans take advantage of a brief reprieve from Dark Winter's wrath.

A danger zone in space above the South Atlantic where lights flash and satellites go haywire; astronauts' first-hand accounts.

The leader of a once mighty lion pride must now battle for their very survival; a look at whether or not this extraordinary lioness can save her family from disaster.

Alaskans take advantage of a brief reprieve from Dark Winter's wrath.

Exploring fossils from a North Dakota site that may reveal what happened when an asteroid struck Earth and wiped out the dinosaurs.

In northern Queensland, nature nerd Dr Ann Jones comes face to face with one of Australia's mightiest predators, the bull shark, and discovers there's much more to them than meets the eye.

A race to find the planet's 60 deadliest creatures.