Under the ice, the water of the Alpine lakes never freezes, and fish can survive the harshness of winter. In February, eels and other fish species are spawning, depositing the eggs that will give life to their next generations. Along fast-flowing mountain streams, ice doesn’t form, and the dipper dives in search of invertebrates, crustaceans, and other tiny prey.

In winter, Europe’s greatest mountain range, the Alps, lies blanketed by snow and ice. For the majestic golden eagles, who make these remote and impressive peaks their home, these are hard times, and food is scarce. But one eagle is lucky: An avalanche results in an unexpected meal.

Just how smart are dolphins? Can they tell their own reflection apart from another dolphin? Here we see examples of "self-directed" behaviors that answer this question.

We all know that crows are smarter than the average bird, but will 007 be able to solve the complex puzzle and retrieve his reward?

By following honeyguides, a species of bird, people in Africa are able to locate bees’ nests to harvest honey. Research now reveals that humans use special calls to solicit the help of honeyguides and that honeyguides actively recruit appropriate human partners. This relationship is a rare example of cooperation between humans and free-living animals.

In the next 35 years, we’ll have to produce more food than all of the world’s production over the last 2000 years combined. So what will the farms of the future look like?

Off the coast of California, an island of floating kelp provides refuge for fish in the open waters. The many small fish then attract larger species, including the ocean sunfish that seek relief from their parasites, and the predatory blue shark.

The harbor seals gather in a sheltered cove to give birth. But even hidden from predators, there is no guarantee of survival, and we witness the tragic death of one newborn that gets trapped in its amniotic sac. Within a few hours, the pups that survive the birth are already into the waves, getting to know their new watery world.

Life can be hard in the Californian desert, but many plants and animals are adapted to survive the hot, dry conditions. Jackrabbits, owls, hummingbirds, and the green stick tree all thrive in this harsh climate as they wait for the rare blessing of rain.

Alive since ancient times, the giant sequoia trees stand colossal and majestic. Deep in the valley, a pair of coyote hunt in the winter snow, while in the Mojave Desert, Joshua trees and cactus plants have adapted to survive the searing heat.

Every fall, the monarch butterflies migrate back to their breeding grounds in California. These fascinating and stunningly beautiful creatures weigh only a gram, yet travel extraordinary distances to complete their lifecycle. In the early spring, deep in the Yosemite valley, the sun warms the wet ground, forming clouds of misty fog.

The Ocean Cleanup is a Netherlands-based, non-government environmental engineering organization that develops technology to extract plastic pollution from the oceans. They have developed a "passive" cleanup system that takes advantage of the natural oceanic forces of wind, water, and currents.

Kelp is a fascinating plant. What we see on the surface has little in common with what's actually there. Californian harbor seals are mammals but they do a lot of hunting underwater.

Everyone's heard of California, but this documentary showcases the state's natural beauty and wildlife. It has a fascinating range of geographical features and is home to many unique species of animals.

In this short animation, produced for primary school children by Green.TV, supported by the Wellcome Trust, we look at the remarkable evolution of the whale from a land-based dog-like animal to the marine mammal that became the world’s largest creature ever.

The series draws to a close with footage of apes, the most direct ancestors of humans. The narrator nicely sums up the meaning of evolution and man's place in nature.

Dolphins are one of the smartest animal species on Earth. In fact, their encephalization quotient (their brain size compared to the average for their body size) is second only to humans. But exactly how smart are they? This video shares some incredible facts about dolphins.

Rhinoceroses, or rhinos for short, are the largest land animals after elephants. Five species remain (two in Africa and three in Asia) and all are endangered as a consequence of the illicit trade of their horns. The importance of rivers is another focus of this segment.

In this beginner-level video, Luana teaches us about plants. She talks about the functions of the various parts of a plant, and offers tips on watering plants that grow indoors and outdoors.

The focus of this segment is on animals of the African savanna. We get to see giraffes and elephants, the largest of the land creatures, as well as cheetahs, the fastest.

The video starts with information about coastal geology and the evolution of birds. It includes amazing footage of white storks, wildebeest, as well as zebras in East Africa's Serengeti region.

World Wildlife Fund: Making sustainability a priority, the Marshik Dairy — a fifth-generation family farm — implemented a new, technologically advanced and energy efficient barn design for their 155 cows. The new design included robotic milking facilities, energy efficient lighting and ventilation, and renewable wind and solar power.

California sea lion communication, mating habits, and past and present threats to their survival are discussed. This segment additionally features amazing aerial photography of their rocky coastal habitats.

Here's a video from the World Wildlife Fund. Traditionally, anaerobic digester systems have not been practical on small dairy farms, but this didn’t stop Sensenig Dairy, a 100-cow farm, from pursuing its goal. Then Sensenig teamed up with the local community to collect enough waste to produce 1,401,600 kilowatt hours of electricity per year from "trash" that would otherwise end up in a landfill.