Perhaps it’s because our furry friends have long provided us with comfort, camaraderie, and unconditional love. Cats and dogs are our unending source of kisses, cuddles, slobber, claws, and laughs. Watch as NATURE shares the stories of pet owners and their beloved animals. From a very special dog named Jerry, to a cat that saved a man’s life, Why We Love Cats and Dogs presents a portrait of some of the most powerful and remarkable connections we experience as humans—the unbreakable bonds with our pets.

Four-time Emmy Award winner, filmmaker and director Ellen Goosenberg Kent kept the 10-month production of NATURE’s Why We Love Cats and Dogs on the right track. Ellen brings a strong visual sense to the art of storytelling and was able to illuminate the dynamic human-pet relationship, revealing how dogs and cats share our emotions in many significant ways.

Update February 19, 2009: Professional dog trainer and behaviorist Sarah Wilson answers Five Good Questions on PBS Engage.

Online content for Why We Love Cats and Dogs was originally posted February 2009.

Photo by Joe Sinnot © EBC

Accidentally or intentionally released pythons and other exotic animals, such as parrots, reptiles, and lizards are inhabiting dry as well as wet habitats, and feeding on or competing with native species. Giant pythons are well-adapted for success in Florida, where the habitat is similar to their Asian home. Although they are non-venomous, pythons are among the largest snakes in the world, reaching up to twenty-six feet long. Their size and power makes them one of the top predators in Florida’s Everglades National Park, taking on even the alligators, and posing a threat to many of the indigenous and endangered species.

NATURE follows teams of scientists and hunters as they use their vast knowledge of snakes and their prey to uncover the impact of the pythons on the park’s fragile ecosystems. Herpetologist Shawn Heflick uses some innovative techniques to observe the mechanics of the snake’s bite, while scientists Stephen Secor and Skip Snow employ advanced technology to analyze the ways in which pythons swallow and digest animals that can be more than half their own body size. Watch as a wild python ingests an alligator whole.

Journey with NATURE as it investigates what comes next in the story of the Invasion of the Giant Pythons.

Crows live everywhere in the world except Antarctica and are a part of myths and legends in many cultures. Their reputation in the stories varies from comical to frightening, godlike or wise, bringers of light and bringers of death, though a “murder” of crows refers to a flock of crows, and not to anything murderous, at all. They may be all these things, but what we are learning is that they are especially smart.

New research has shown that they are among the most intelligent animals on the planet. They use tools as only elephants and chimpanzees do, and recognize 250 distinct calls. One particular talent they have been discovered to possess is the ability to recognize individual human faces and pick them out of a crowd up to two years later – a trick that might make even Hitchcock shiver with fright.

They thrive wherever people live and have used their great intelligence to adapt again and again to a constantly changing world. Some memorize garbage truck routes, and follow the feast from day to day. Others drop nuts in the road and wait for passing cars to crack them open. And some build their nests from items we throw away – like wire clothes hangers.

These are social birds that mate for life and raise their young for up to five years. And they learn from each other’s misfortunes. When one is killed in a farmer’s field, it’s not uncommon for them to change entire migratory patterns so that no crows fly over that field for as long as two years.

These birds might have a scary reputation, but what may prove to be the scariest thing about them is how much they know about us, and how little we know about them!

A Murder of Crows premieres Sunday, October 24 at 8:00 PM.

NATURE’s two-part special Dogs That Changed the World tells the epic story of the wolf’s evolution, how “man’s best friend” changed human society and how we in turn have radically transformed dogs.

From the tiniest Chihuahua to the powerful and massive English Mastiff, modern domesticated dogs come in a bewildering array of shapes and sizes, with an equally diverse range of temperaments and behaviors. And yet, according to genetics, all dogs evolved from the savage and wild wolf — in a transformation that occurred just 15,000 years ago.

In Part One, “The Rise of the Dog,” you’ll learn about how the domestication of dogs might have taken place, including the theory of biologist Raymond Coppinger that it was the animals themselves — and human trash — that inspired the transformation. The genetic analysis of Peter Savolainen of the Royal Institute of Technology in Sweden has placed the origins of domesticated dogs — and those of the first dog — in East Asia. You’ll also discover 14 dog breeds that controversial genetic studies show are the most ancient — and the best living representatives of the ancestors to all living dogs.

Preview Part Two: Dogs by Design

Over 400 breeds of dog are recognized around the world, each unique for its personality, habits, and form. Most of these breeds exploded onto the scene over the past 150 years, spurred by the Victorian-era passion for the “dog fancy” — the selective breeding of dogs to enhance particular characteristics. By tinkering with its genetics, humans made the dog the most varied animal species on the planet — and also created a host of hereditary health problems.

Despite the plethora of new shapes and sizes, dogs have retained the instincts bred into their ancestors by thousands of years of work: the urge to herd or hunt, to dig and to guard. In Part Two, “Dogs by Design,” you’ll discover how these hard-wired behaviors help different types of dogs, from hounds to herders, excel at different tasks (and why it can sometimes be so difficult to train them to do otherwise). You’ll also learn how dogs’ finely tuned senses are serving humans and saving lives. Buy the DVD. This film premiered April 2007.

Because hummingbirds live their lives in fast forward, much of their fascinating world is typically lost to human perception. But using cameras able to capture over 500 images a second, the hummingbirds’ magical world can finally be seen and appreciated. Amazing footage shows these little powerhouses are far more than delicate nectar gatherers — they are also deadly predators. And watch as the birds display their elaborate mating rituals, showing off with nose dives that subject them to over ten G’s of force — enough to cause an experienced fighter pilot to black out!

These tiny marvels dazzle and delight bird watchers all over the world, and NATURE reveals their stunning abilities as they have never been seen before.

In Supersize Crocs, Rom takes viewers along as he sets off on his own hunt to find the last of the leviathans. Venturing to Ethiopia’s Lake Chamo, the riverbanks of India’s northern border with Nepal, and to the Adelaide River of Australian outback, Rom hits the hotspots of supersize croc habitats as he searches for signs of life among the brackish waters. Rom will share with viewers his insight and fascination with the cryptic world of crocs. Along the way, viewers will learn about ancient croc survival skills as well as how crocs are ideally designed to be the most successful freshwater predator.

Will he find his supersize croc among the three titans of the croc world: the Nile crocodiles, saltwater crocodiles and gharials? Tune in to find out.

To order a copy of Supersize Crocs, please visit the NATURE Shop.

Online content for Supersize Crocs was originally posted February 2007.

NATURE travels around the world to visit some of these fascinating primates. From tiny pygmy marmoset in South America to aggressive baboons of Africa and compassionate toque macaques in Sri Lanka, Clever Monkeys challenges many ideas about what is purely “human.” Buy the DVD. This film premiered November 9, 2008.

Since the 2003 invasion of Iraq, news about the fate and future of this Middle Eastern country has been at the forefront of our national consciousness, making an impact on our daily lives, appearing in every newspaper and news program, the subject of endless numbers of personal and political discussions. But if you think you’ve heard every imaginable story about life within Iraqi borders, think again. There is at least one major element in this geopolitical drama that the American media has mostly overlooked, and it lies at the cross section of regional politics and the natural environment. NATURE’s Braving Iraq unravels this tale about what was once one of the richest and most important wetlands in the world – from its virtual destruction by a ruthless dictator to its exciting, new prospects for a miraculous recovery.

As recently as the 1980’s, Iraq’s Mesopotamian Marshes were reminiscent of the Garden of Eden – indeed, many biblical scholars believe they are one and the same. Fed by the combined waters of the Tigris and the Euphrates rivers, this enormous marshland of over 6,000 square miles dominated southern Iraq. For more than 7,000 years, these wetlands provided a bountiful home for both wildlife and humans. A large population of indigenous people, the Ma’dan Tribes known as Marsh Arabs, had thrived there for centuries. But in the 1990’s, due to political conflict, Saddam Hussein attempted to eradicate them – not through systematic extermination, but by destroying the marshes on which they depended for survival. Massive canals were dug, diverting river water away from the wetlands and towards the Persian Gulf. Huge embankments were built to prevent water from entering the marshes. What had been a green paradise twice the size of the Everglades shrank to less than 10% of its original size. Most of it was transformed into a parched, lifeless desert. The wildlife and the people were forced to leave.

But the story did not end there. Due to the imagination and the efforts of a coalition of individuals, restoration of the marshes has become more than a dream. Civil strife, serious security incidents and droughts make for slow progress, but various groups are chipping away at the embankments, trying to successfully flood the marshes once again. Azzam Alwash, an engineer raised on the banks of the Euphrates, left Iraq for America to escape from Saddam’s regime, but he has returned to undertake one of the largest habitat recreation projects in the world. Filmmakers David Johnson and Stephen Foote follow Azzam, chronicling his efforts to breathe new life into the green paradise he remembers from his childhood, while also navigating the inherent dangers of working in a dangerous and politically volatile region.

Is there any hope that such a massive ecosystem can be brought back to life? Have the exiled rare birds of the marsh, such as the marbled teal and the Basra reed warbler, survived? And will they return to their old territory? Success is uncertain, but some Iraqis feel that the fate of the country itself is tied to the fate of the marshes – and as small signs of hope for natural recovery begin to appear, Iraq’s political future seems to brighten as well.

Watch as a California town overrun with skunks deals with their furry problem, and see what life is like for an evolutionary biologist in New Mexico who runs one of the few sanctuaries for skunks. Meet a researcher on the sandy shores of Martha’s Vineyard who stalks her striped specimens at night, and a woman in Ohio who runs a shelter and adoption agency for abandoned pet skunks. Is That Skunk? paints a complete portrait of the misunderstood skunk family, Mephitidae, and the people who love them.

To order a copy of Is That Skunk? please visit the NATURE Shop.

Online content for Is That Skunk? was originally posted January 2009.

Photo credit: Cici Clark / © WNET.ORG

In the remote area of Death Valley National Park known as Devil’s Hole, six men suit up for a long day of desert exploration. But these explorers are swapping their dusty hiking boots and water bottles for neoprene wetsuits and oxygen tanks.

As NATURE’s Life in Death Valley reveals, the men are part of a specialized team of divers who assemble in this 40-acre pocket of Death Valley four times a year to monitor the population of the park’s most surprising desert creature: the critically endangered Devil’s Hole pupfish. Death Valley may seem an unlikely habitat for a fish, but this tiny species has managed to thrive here for thousands of years despite epic changes in its environment.

When summer temperatures spike to 120 degrees, it’s difficult to imagine Death Valley in an ice age. But twenty thousand years ago, the valley rested beneath a vast lake system where the ice-age ancestors of these pupfish swam. As the climate warmed, the lake dried and formed separate pools, and the fish that were once part of the same parent population began to develop unique characteristics in response to their individual environments, eventually evolving into several distinct species of pupfish.

But it’s the fragile Devil’s Hole species that has made the biggest waves throughout history, primarily due to the place it calls home. Located in southern Nevada, the “hole” itself is a fissure in the earth’s surface that split open 60,000 years ago to reveal an astonishing underworld: a water-filled limestone cavern. Ironically, beneath the hottest, driest place in the Western Hemisphere stretches a vast aquifer system. The opening at Devil’s Hole is one of the few places in Death Valley where the water from this system meets the surface.

“This is the only place on the planet where this fish exists naturally,” says Zane Marshall, head diver for the Devil’s Hole Pupfish Recovery Team. “Scientists have estimated that it has been in isolation here in excess of 25,000 years.”

Marshall’s team is part of a larger recovery effort that includes representatives from the National Park Service, the Department of Fish and Wildlife, and Nevada’s Division of Conservation. “This pupfish is the most restricted vertebrate species in the world,” says Marshall.

It was that exact notion that prompted President Harry Truman, in 1952, to protect the unique pupfish and its habitat by designating Devil’s Hole a disjunct part of Death Valley National Monument. For nearly two decades, the fish enjoyed a protected haven.

But by the late 1960s, development and nearby farming beyond the boundaries of the monument began to take a toll on the water levels in Devil’s Hole. As the pupfish do most of their feeding and spawning on an algae-carpeted limestone shelf just a few inches below the surface, a small drop in the water level was all it took to bring the fish to the brink of extinction.

What ensued was a bitter contest over water rights that pitted developers against conservationists and the federal government against a corporate farm. In the end, the fish reigned victorious. In 1976, the U.S. Supreme Court issued a landmark ruling that protected not only the fish but also their fragile habitat by specifically stating that water levels in Devil’s Hole must remain high enough to completely cover the spawning shelf. As a result of the ruling, development was halted, and the fish became one of the very first species to be protected under the Endangered Species Act.

Since then, Devil’s Hole has been cordoned off from park visitors by a chain-link fence that runs the perimeter of the hole. Only members of the recovery team are permitted access in order to perform quarterly counts of the fish. From 100 feet beneath the surface, the team works their way up in pairs, counting and measuring every fish they see. This provides them with an index of how the population is doing.

Despite 30 years of federal protection, recent counts suggest grim news: the fish’s population is once again plummeting. Linda Manning, a biologist for Death Valley National Park has been working closely with the Pupfish Recovery Team. “Right now we are very concerned because we recently had the lowest count in 32 years — only 123 fish,” she reports.

This time, however, the reasons for their decline are not so clear. Due to its protected status, study of Devil’s Hole has been extremely restricted. “We don’t yet understand everything that is going on in this system,” says Manning. “It’s a real puzzle. You wonder what the dynamics are. What’s impacting the fish? How are they making it? We’re just starting to get a handle on it, but there’s just still so much more to know.”

What they do know is that it is a harsh environment for a fish. The water temperature is 93 degrees Fahrenheit, food sources are extremely limited, and sunlight only hits the surface of the spawning shelf four months out of the year. “It’s pretty amazing that they’ve actually survived for thousands of years in this environment,” says Manning. “I just hope they can continue.”

In addition to conducting quarterly counts of the fish, the Park Service has installed monitoring wells near Devil’s Hole to keep an eye on the water levels, which have been dropping gradually over the past 14 years. Development and groundwater pumping in nearby Pahrump, Nevada, has long been suspected of affecting the water level in Devil’s Hole, though many Pahrump officials deny the allegations.

If the team doesn’t find a solution soon, the devastating effects may be far-reaching. “We definitely believe the pupfish are an indicator for the health of this system,” offers Manning. “When you start poking holes in the fabric of an ecosystem, over time it’s going to tear, and the impacts will be felt by everyone.”

Before that happens, the team will continue to do all they can to ensure the Devil’s Hole pupfish keep hold of their well-earned reputation as resilient survivors.