More than 200 caves play host to an unmatched array of marine life and coral formations in this underwater kingdom 40 kilometres from Belize City. It's a deep blue wilderness brimming with rare, exotic fish, eagle rays, sharks, and huge green morays.

Clear waters, deep reefs, dangerous caves, and tunnels draw divers to the island of Cozumel on Mexico's east coast. The Caribbean Sea port is home to multicoloured schools of fish, bull sharks, and gigantic sea turtles.

During the last few weeks of the dry season, the prides stick close to the only available water in the river. But in Luangwa, that proximity spells danger – especially when the scent of a hippo kill compels the Hollywoods to cross the river.

Lewa Conservancy is working to return elephants to territory from Mt. Kenya to Samburu National Park. They've also created an elephant exclusion zone to try and restore a damaged ecosystem. Radio tracking collars are used for both initiatives to help conservationists better understand the elephants' needs – and to see if they're returning to their natural corridors.

Elephant hunting has been banned in Kenya for 40 years. Organized gangs of armed poachers are still targeting elephants, illegally hunting them and selling their ivory tusks on the black market. Environmentalists and conservationists are sounding the alarm.

The Lake Erie Watersnake is currently on the brink of extinction, and researchers have been fighting to get it back. And it looks like it's finally working – thanks to the round goby. Grad student Lizzy Mack is heading out on day trips to catch bucket loads of the snakes, collect measurements, and inject them with small microchips to track them along their way, all while dodging bites from some of the crankiest snakes around.

Lewa Conservancy is working to return elephants to territory from Mt. Kenya to Samburu National Park. They've also created an elephant exclusion zone to try and restore a damaged ecosystem. Radio tracking collars are used for both initiatives to help conservationists better understand the elephants' needs – and to see if they're returning to their natural corridors.

Elephant hunting has been banned in Kenya for 40 years. Organized gangs of armed poachers are still targeting elephants, illegally hunting them and selling their ivory tusks on the black market. Environmentalists and conservationists are sounding the alarm.

Experience a roller coaster of emotions and growing pains as the sanctuary's orangutans move through six grades toward their release into the wild. Discover how Dilla's fate suddenly changes, and watch as big boy Beni goes on an unwelcome diet.

Follow a host of sharks with extraordinary abilities that allow them to thrive in the most adverse conditions around the globe. Observe nearly blind Greenland sharks made for life in freezing Arctic waters, and another species that can walk on land.

Get a front-row seat to the planet's biggest biomass migration, the annual 1,000-mile sardine run along South Africa's east coast. See billions of these tiny fish run a gauntlet of hungry predators, including stealthy seals and dive-bombing gannets.

Eastern Grey kangaroos are prolific breeders, but bringing up baby is fraught with challenges. Predators, climate extremes, and lively joeys mean kangaroo mothers face a daily struggle to keep their young alive.

Waters flood Southern Florida's mangroves and marshes. Many of the 600 animal species that live in the Everglades disperse during this time, expanding their hunting and breeding grounds.

Lewa Conservancy is working to return elephants to territory from Mt. Kenya to Samburu National Park. They've also created an elephant exclusion zone to try and restore a damaged ecosystem. Radio tracking collars are used for both initiatives to help conservationists better understand the elephants' needs – and to see if they're returning to their natural corridors.

Elephant hunting has been banned in Kenya for 40 years. Organized gangs of armed poachers are still targeting elephants, illegally hunting them and selling their ivory tusks on the black market. Environmentalists and conservationists are sounding the alarm.

The all-female Hollywood pride have been in exile after being attacked by the four Nomad brothers. But their leader, Ava, decides to lead her family south to the heart of their territory for a showdown with the Nomads.

Follow a host of sharks with extraordinary abilities that allow them to thrive in the most adverse conditions around the globe. Observe nearly blind Greenland sharks made for life in freezing Arctic waters, and another species that can walk on land.

Get a front-row seat to the planet's biggest biomass migration, the annual 1,000-mile sardine run along South Africa's east coast. See billions of these tiny fish run a gauntlet of hungry predators, including stealthy seals and dive-bombing gannets.

Eastern Grey kangaroos are prolific breeders, but bringing up baby is fraught with challenges. Predators, climate extremes, and lively joeys mean kangaroo mothers face a daily struggle to keep their young alive.

Waters flood Southern Florida's mangroves and marshes. Many of the 600 animal species that live in the Everglades disperse during this time, expanding their hunting and breeding grounds.

Lewa Conservancy is working to return elephants to territory from Mt. Kenya to Samburu National Park. They've also created an elephant exclusion zone to try and restore a damaged ecosystem. Radio tracking collars are used for both initiatives to help conservationists better understand the elephants' needs – and to see if they're returning to their natural corridors.

Elephant hunting has been banned in Kenya for 40 years. Organized gangs of armed poachers are still targeting elephants, illegally hunting them and selling their ivory tusks on the black market. Environmentalists and conservationists are sounding the alarm.

Experience a roller coaster of emotions and growing pains as the sanctuary's orangutans move through six grades toward their release into the wild. Discover how Dilla's fate suddenly changes, and watch as big boy Beni goes on an unwelcome diet.

Follow a host of sharks with extraordinary abilities that allow them to thrive in the most adverse conditions around the globe. Observe nearly blind Greenland sharks made for life in freezing Arctic waters, and another species that can walk on land.

Get a front-row seat to the planet's biggest biomass migration, the annual 1,000-mile sardine run along South Africa's east coast. See billions of these tiny fish run a gauntlet of hungry predators, including stealthy seals and dive-bombing gannets.

Eastern Grey kangaroos are prolific breeders, but bringing up baby is fraught with challenges. Predators, climate extremes, and lively joeys mean kangaroo mothers face a daily struggle to keep their young alive.

Waters flood Southern Florida's mangroves and marshes. Many of the 600 animal species that live in the Everglades disperse during this time, expanding their hunting and breeding grounds.

Lewa Conservancy is working to return elephants to territory from Mt. Kenya to Samburu National Park. They've also created an elephant exclusion zone to try and restore a damaged ecosystem. Radio tracking collars are used for both initiatives to help conservationists better understand the elephants' needs – and to see if they're returning to their natural corridors.