Dr. Jan Pol has been a practicing veterinarian for more than half his life. In 1981 he and his wife, Diane, opened a vet business out of their home, and over the years it has grown to service more than 19,000 clients. Set in Central Michigan's farm country, this reality series follows the work done at Pol Veterinary Services. Specializing in large farm animals, Dr. Pol treats horses, pigs, cows, sheep, alpacas, goats, chickens and even an occasional reindeer. The program also features Dr. Brenda Grettenberger, who has worked with Dr. Pol since 1992.

Investigating the world's most clever and savage predators.

When bears, wolves and foxes are your only neighbors, life can be pretty lonely. Add minus-60-degree days and a constant battle for the most basic necessities, and you have the daily challenges of people who live in remote corners of Alaska. This series takes viewers deep into an Alaskan winter to meet tough, resilient residents as they try to stay one step ahead of storms and man-eating beasts to survive the season. The closest neighbor to Sue Aikens is more than 300 miles away. Eric Salitan subsists solely on what he hunts and forages. Chip and Agnes Hailstone catch fish for currency in bartering for supplies, and Andy and Kate Bassich use their pack of sled dogs for transportation. Also highlighted is a time of year not always part of what viewers see in Alaska: spring! Ice is breaking, animals are waking, and residents face new tests before deep cold returns.

Dream adventures turn into hellish nightmares for the travelers featured in this series, which recounts through firsthand interviews and re-enactments terror-filled experiences of being arrested in a foreign country, usually for drug smuggling, and how they coped with the resulting lengthy prison terms. Viewers also hear from people directly involved with the arrests, whether it's the undercover agents gathering the evidence against the suspects, or the people making the drug dealing offers.

Silicon Valley circa 1990s was a technology breeding ground that attracted visionaries and charlatans alike, spawning some of the world's most influential people and recognizable brands. Set during that time, this six-part limited series follows the turbulent ride of three different companies whose founders were trying to change the world using the emergent technology of the internet. Creator, director and executive producer Matthew Carnahan ("House of Lies") employs a hybrid of scripted storytelling and documentary interviews with the key players whose stories are dramatized in the show. Emmy winner Bradley Whitford ("The West Wing") leads the ensemble cast.

One of the largest and most popular zoos in the U.S., Ohio's renowned Columbus Zoo and Aquarium and its conservation park The Wilds, houses more than 10,000 animals on 12,000 acres. It's also the part-time home of beloved wildlife guru Jack Hanna, the zoo's director emeritus. Now, Nat Geo Wild is taking viewers inside the grounds and allowing them to experience what visitors can't: compelling, heartwarming stories, and behind-the-scenes moments and adventures. "Secrets of the Zoo" introduces both the animals and the legions of workers who create unforgettable connections between people and wildlife.

This Emmy-nominated series is designed to mess with the ultimate supercomputer. Host Jason Silva reveals how brains process information related to topics like stress, addiction, competition, food, trust and language. Interactive games and hidden-camera experiments capture hilarious and shocking results, and viewers get real-world takeaways -- how to improve memory, get a better night's sleep, make more money -- to use in everyday situations.

Fishing for bluefin tuna is a way of life for many residents of Gloucester, Mass. "Wicked Tuna" takes viewers into the unrelenting North Atlantic waters infamously spotlighted by the novel-turned-feature film "The Perfect Storm," to follow captains who are relied upon by their families, their shipmates, and by Gloucester itself, to haul in boatloads of the large but elusive bluefin. The pressure to deliver is unforgiving -- the fishing season is short and tuna populations are dwindling -- but one "monstah" catch can reel in just as large of a payday.

Throughout America's coastline shark attacks are on the rise. Many occur in quick succession at new and surprising locations. As vacationers, scientists and locals are all desperate to uncover what is causing the upsurge, National Geographic Channel investigates the attacks to see what is affecting some of nature's most feared fish. The deep-sea saga employs underwater photography, news archives and testimony to deep dive into mysterious and deadly recent shark attacks.

Alaska's deadliest thrive in one of America's last wild frontiers.

Put up your dukes -- er, paws -- and prepare to discover epic, bone-shattering clashes between some of the world's deadliest predators. From lions, tigers and bears to meerkats, mongoose and mice, the series features testosterone-induced battles between some of the biggest, baddest and often surprising fighters in the animal kingdom, revealing the extraordinary motivations and strategies that fuel each incredible brawl.

Homeland Security at JFK International Airport deals with daily issues ranging from fraudulent visas to human trafficking.

This series helps change how people look at World War II thanks to hundreds of hours of video that have been declassified and fully restored in high definition. Soldiers on the front lines, secret operatives, resistance fighters, and private citizens shot the footage, some of which has never been seen, that gives viewers a firsthand look at what went on during times of battle. Episodes detail the battle over Stalingrad that was a key turning point in the war and show Japanese pilots on the morning of Dec., 7, 1941, preparing for the attack on Pearl Harbor.

Exploring the resilient and deadly animals that call Australia home.

The producers of National Geographic Channel's hit series "Life Below Zero" are behind "Port Protection," which profiles individuals trying to survive way above the Lower 48. Surrounded by the North Pacific, Port Protection is a remote community tucked into the northwest corner of Prince of Wales Island, Alaska. The approximately 100 residents who call the rugged, unforgiving land home push the limits of survival, living an isolated and risky existence of self-reliance with no roads, government or law enforcement. However, they think the risk is worth the profound reward: a world of beauty with the security of community without the constraints of bureaucracy.

Enhanced episodes of "The Incredible Dr. Pol."

Suspenseful nature stories begin just before sunset and end just after sunrise; from Costa Rica to Indonesia to the swamps across the United States, creatures of the night battle for survival when the sun goes down.

Africa is home to some of the deadliest creatures of all, and in this series, you'll see them.

From the Arctic Ocean and its isolated Islands to the bleak, barren tundra and frozen forests of the taiga, the Arctic region is locked in ice for more than half of the year; in summer, this land of contrast bursts into life.

The "Dog Whisperer" is back, this time to answer emergency calls from communities terrorized by unruly canines. Renowned dog behavior authority Cesar Millan is beckoned by the relatives, friends, neighbors or co-workers of someone whose four-legged menace has turned lives upside down. In each episode, Millan meets with the whistle-blowers in a briefing session, then he evaluates both the pets and the owners through impromptu visits to the neighborhood locations to see dogs display their doggone behavior and watch how owners react. After rehabilitation programs are set up, Cesar uses surveillance cameras to track progress and ensure a lasting solution. The final test comes when all parties gather together in the community -- owners equipped with the knowledge and tools Cesar has provided, and dogs ready to prove they did learn new tricks.