As the only creatures on earth to breed in the Antarctic winter, their survival, as well as those of their chicks, is put in jeopardy when the temperature falls to 40 below. So, instinctively, emperor penguins all converge on the same central point and begin to form a huddle. As those on the outside take the brunt of the cold, those on the inside take tiny steps that move the huddle in waves.

Get a look at some of the planet’s great gatherings, creatures that come together in inconceivable numbers — sometimes in millions, billions, even trillions. In the process, a kind of super-organism is created in which individual intelligence is superseded by a collective consciousness that shares information and moves with a single purpose for the benefit of all.

Hairdresser Sherri Tippie, the top live trapper of the species in North America, rescues unwanted beavers in the Denver suburbs and then places them with farmers and beaver enthusiasts who eagerly provide new homes for them.

A growing number of scientists, conservationists and grassroots environmentalists have come to regard beavers as overlooked tools in the effort to reverse the disastrous effects of global warming and worldwide water shortages. View these industrious rodents, once valued for their fur or hunted as pests, in a new light through the eyes of this novel assembly of beaver enthusiasts and “employers.”

Beavers are devoted to their work as dam builders and they are born equipped and ready for the job. Leave it to Beavers tells the story of beavers in North America – their history, their near extinction, and their current comeback as modern day eco-heroes.

A growing number of scientists, conservationists and grass-roots environmentalists now regard beavers as overlooked tools when it comes to reversing the disastrous effects of global warming and worldwide water shortages. Using their skills as natural builders and brilliant hydro-engineers, beavers can transform and revive landscapes.

After two years in the field in Japan documenting the lives of a snow monkey troop, producer and cinematographer Joe Pontecorvo compiled over 700 hours of footage. In this segment, learn about the post-production process, from video and sound editing, to color correction, to music composition.

As winter months fade away, the forest becomes a nursery for this troop of snow monkeys: The newborns are full of energy and curiosity, and are blissfully unaware of dangers or troop politics. Snow Monkeys airs Wednesday, April 23 at 8 p.m. (ET) on PBS (check local listings).

Japan's Jigokudani became a sensation when hot springs were constructed for the Hell Valley snow monkey troops. The monkeys get important help from the hot springs in the valley, fed by warm volcanic waters, but their survival is a communal effort in a complex society of rank and privilege where each knows their place.

The troop that grooms together, stays together: Get to know the social ins and outs of individuals within a 160-member snow monkey troop led by Kuro-san, a young male still new to the job and something of a solitary grouch. Snow Monkeys airs Wednesday, April 23 at 8 p.m. (ET) on PBS (check local listings).

"Snow Monkeys" producer and cinematographer Joe Pontecorvo sought to capture the life of Japanese Macaques deep within the snow-covered mountains of Northern Japan, in a valley named Jigokudani, meaning “Hell Valley”. Pontecorvo and his wife Nimmida Pontevorco followed a snow monkey troop, 160 members in all, for nearly two years to truly get to know these fascinating creatures.

In the frigid valleys of Japan’s Shiga Highlands, a troop of snow monkeys make their way and raise their families in a complex society of rank and privilege where each knows their place. Their leader is still new to the job and something of a solitary grouch. But one little monkey, innocently unaware of his own lowly social rank, reaches out to this lonely leader.

Over two years of patience on Joe Hutto's part resulted in first displays of trust by a herd of wild mule deer. But once Hutto won full acceptance from the herd's leader, a doe he called Raggedy Anne, he could move among the individuals in the herd and no one paid attention. He had become part of the family. Touching the Wild airs Wednesday, April 16 at 8 p.m. (ET) on PBS (check local listings).

A profound moment of bonding occurs for Joe Hutto when mule deer Rag Tag, the doe herd leader's daughter, begins to groom him, something that only occurs within a deer family. During his seven year journey of bonding with a wild mule deer herd, Joe Hutto came to appreciate the animals' profound intelligence, particularly during displays of curiosity. Touching the Wild airs Wednesday, April 16 at 8

While survival during winter is never a guarantee for wild mule deer, those who endure the harsh months always return to their range. Joe Hutto is included in a profound moment of reunion among a mule deer herd, in particular the introduction of a young deer Molly and her twin to the their extended family. Touching the Wild airs Wednesday, April 16 at 8 p.m. (ET) on PBS (check local listings).

For writer, artist and naturalist Joe Hutto (“My Life as a Turkey”), there is no such thing as conducting a typical research project. After a chance encounter with a young mule deer, Hutto would embark on a journey of bonding that would consume over seven years of his life. Touching the Wild airs Wednesday, April 16 at 8 p.m. (ET) on PBS (check local listings).

Joe Hutto’s idea of research is anything but normal, dedicating seven years of his life to becoming a wild mule deer.

Left disabled without fins, flippers, beaks, or tails because of disease, accidents, or even human cruelty, some animals need what amounts to a miracle. Amazing prosthetics made possible by the latest engineering and technology are able to provide just what they need, and scientists are finding that innovations created in the process are benefiting both animals and humans.

Sea Turtle Inc. Director Jeff George introduces Allison, a 70-pound sea turtle who lost three of her flippers in a predator attack. Thanks to the advocacy of a 21-year-old intern, Allison has received a prosthetic rudder made out of carbon fiber to create drag in the water and allow her to swim freely.

Don the crow suffered an injury to his beak and struggled to eat. One year or so after the incident, Don was given a new beak made out of dental acrylic, with careful attention to proper lineup and ware of the upper and lower beaks.