Visit New York City's Union Square Holiday Market. Meet the people there. Hear the sounds, see the sights and enjoy what has become a popular Christmas tradition!

In this final installment of the series, a white Kermode bear encounters a black bear while fishing. Observe their behavior. Look and see for yourself what ensues!

In order to fatten up before winter sets in, brown bears feast upon salmon migrating upstream to spawn. Enjoy!.

The salmon that make it upstream mate and then die of exhaustion. Meanwhile, many other animals are lurking and waiting to feed.

Rozalia Project knows all about marine debris. Do you? Take a look at their wrap-up video from Expedition CLEAN on the Gulf of Maine in August of 2014.

The great white shark and killer whale are both infamous marine predators. Normally they leave each other alone, but one day, biologists off the cost of California witness something unprecedented.

David Gallo shows jaw-dropping footage of amazing sea creatures, including a perfectly camouflaged octopus, and a Times Square’s worth of neon light displays from fish who live in the blackest depths of the ocean.

During the night, Sam Gruber's team of biologists has captured a young tiger shark, a perfect candidate for their scientific research.

When wolves were reintroduced to Yellowstone National Park in the United States after being absent nearly 70 years, the most remarkable "trophic cascade" occurred. What is a trophic cascade and how exactly do wolves change rivers? George Monbiot explains the process.

More stunning footage from Alaska shows, up close and personal, the brown bears in action - hunting for salmon and caring for their young. Enjoy!

Seattle artist Matt Sellars shows off the Clovis Point, a skateboard of his own design. Check out a few scenes from its construction and test drive!

In a recent trip across the Sudanese border into rebel-held territory in Sudan’s Nuba Mountains, George Clooney witnessed rocket attacks and the effects of aerial bombardment by the Sudanese regime against the Nuban people. This trip diary was written and directed by George Clooney in the field with the Enough Project.

In this episode, Doc Gruber and a colleague are testing a shark repellent. If effective, it could help save the lives of divers, swimmers and surfers all over the world.

Rosetta revisits the exciting scientific discoveries she has made during her time at Comet 67P/Churyumov-Gerasimenko, including the successful search to find Philae. Now it's time to start preparing to descend to the comet for the end of her extraordinary mission.

WWF: Long-distance swimming puts polar bears at risk of drowning due to fatigue or rough seas. Cubs are at even greater risk because their smaller body size and limited body fat leaves them more prone to hypothermia, and they don’t have the energy reserves of an adult bear.