Chris Morgan travels to the far north of Alaska, the tiny North Slope town of Kaktovik. It’s early November and winter is coming on. But each year, the polar bears struggle for extended periods on dwindling fat reserves, waiting for the opportunity to hunt on sea ice that takes longer to freeze. In early spring, Morgan joins local hunters in Barrow, the northernmost city in Alaska, as they go out on their own hunts, facing some of the same challenges as the bears. In late spring, Morgan travels to the North Slope of the Brooks Range, where countless thousands of caribou cover the ground for miles. The grizzlies are waiting for them, as they have for thousands of years. Buy the DVD. This film premiered May 22, 2011.

Chris Morgan and Joe Pontecorvo set up camp at a remote spot in the heart of Alaskan wilderness, alongside the largest concentration of grizzlies in the world. It is June in the Alaska Peninsula. The sun sets well into night and bears are taking advantage of the long days to feed, mate, and raise new cubs. Morgan tracks their progress as they feast on the riches of the season and re-establish the complex hierarchal social dynamics of bear society. Along the way, he experiences close encounters with bears, observing brutal battles among males during mating season as well as tender moments between a grizzly mom and her cubs. Watch full episode. Buy the DVD. This film premiered May 8, 2011.

Chris: “This female and cubs grazed right by us one day as we sat 80 yards away from her in a meadow. In bear habitat, bears call the shots. She did the approaching, not us, and often in this area, the best course of action is to remain very calm and still to let the bears pass without causing her any anxiety. I’ve spent my career teaching about bear conservation and how to be safe in bear country, and I’ve spent thousands of hours among Alaska’s coastal bears over the last decade, so I want to share a note regarding the very special coastal brown bears of the Alaska Peninsula and the context of their behavior. The coastal brown bears (Ursus arctos) that we filmed in SW Alaska have access to healthy runs of salmon which means that these normally solitary animals have become quite tolerant of each other over a rich food resource. In certain situations, they seem to extend that tolerance to humans, and will frequently come quite close to people during their everyday feeding activities. Some of these bears in this area have seen people before, and have not had a reason to treat humans as anything other than a pretty neutral species. They don’t associate people with food, and that is critically important. Some of the bears are human-habituated – like this female – she’s well used to being on the same meadow as humans and she knows we pose no threat, or have any food to offer!

These bears are socially very different to grizzly/brown bears (Ursus arctos) in the interior (e.g. Denali, or in the Lower 48 Yellowstone, Glacier etc), where a much larger buffer space is advised. Generally speaking, close-up interactions with bears should be avoided at all cost (Wildlife + Distance = Safety). Situations can vary immensely and a knowledge of bear behavior is essential when determining the best course of action.

These bears are calmly walking by with incredible tolerance as they graze. Our calm response to their approach means safety for bears and people. For more information on bear safety, please go to our Grizzly Bear Outreach Project (GBOP):

It’s finally here — time for us to share our incredible Alaskan adventure with the world through Bears of the Last Frontier. It has been quite the journey. The film has been nearly two years in the making, and for both of us it has become an unforgettable part of our lives. Over the course of a year and a half we traveled well over 3000 miles across Alaska and shot 500 hours of footage for this epic three-hour PBS Nature series. We spent many, many months in bear country – piecing together the lives of these fascinating animals by observing and filming them, and by living in bear country, among the animals and people that share bear habitat.

When Joe and I met nearly ten years ago (coincidentally in Alaska) our minds reeled with the possibilities for collaboration. A filmmaker and an ecologist, and a combined dream to have a huge impact for wildlife conservation through the magic of film. The opportunity to work with PBS Nature has been a dream, and has resulted in three beautiful episodes we hope you’ll love.

We’ve both worked all over the world for the last twenty plus years — Joe as an award-winning wildlife filmmaker, and me as a conservation ecologist. Joe has created dazzling films on an array of epic subjects — from tigers to Asian elephants, and my work has focused on wildlife research and environmental education — mostly about the bears of the world. I’ve also guided hundreds of people on expeditions to see polar bears and grizzly bears. We’ve both witnessed the powerful emotions that these animals can trigger in people, which is why they make such great representatives for conservation, and such great characters in film!

Alaska harbors all three of North America’s bear species, from three hundred pound black bears to polar and brown bears weighing well over half a ton. It is home to the highest mountain on the continent, vast glaciers, immense forests, and a level of isolation that can be found nowhere else in the United States.

And it’s big. This northernmost state is the same size as the next three largest states combined (California, Texas and Montana).

Alaska’s wilderness allowed us to step back in time on a journey that took us through five major ecosystems and the habitats of its three bear species. It was also a journey that put us to the test as we hiked, camped and lived among the biggest bears in the world, chased black bears through the streets of Anchorage, followed grizzlies on the prowl for immense caribou herds, and searched for polar bears miles out on the pack ice. In every one of these locations bears have adapted impressively to their surroundings.

We’re hoping that, as you wander through this website and sink yourself into the series, you will feel immersed in the world of the bear. It is a truly wondrous place.

We also hope that you might be inspired to learn more. Bears represent wildness more than any other species, but we cannot take that wildness for granted — it will take determination, passion, and imagination to ensure that future generations can enjoy a world that includes bear habitat.

Be sure to check out the wonderful organizations listed under resources for ways to learn more. We’re all in this together. And remember — what’s good for bears, is good for people!

We’re so glad you’re along for the adventure!

Chris Morgan, Ecologist
Joe Pontecorvo, Filmmaker

Order: Carnivora

Family: Ursidae

Genus: Ursus

Species: arctos

Is it a brown bear or a grizzly? The answer is that all grizzlies are brown bears, but not all brown bears are grizzlies. The grizzly is a North American subspecies of brown bear with the Latin name Ursus arctos horribilis. The correct scientific name for a grizzly is “brown bear,” but only coastal bears in Alaska and Canada are generally referred to as such, while inland and Arctic bears and those found in the lower 48 States are called grizzly bears.

Size and Weight: Walking on all fours, brown bears have a height of about 3.5 feet (just over 1 meter). They can reach heights of 6-7 feet (1.5-2.5 meters) when standing on their hind legs. There are regional size differences among bears; brown bears are generally larger in the north—likely due to the colder climates. The largest of the brown bears, is the Kodiak bear (Ursus arctos middendorffi), is found only in the Kodiak archipelago islands along the southeastern coast of Alaska. Kodiaks can stand more than 10 feet (3 meters) tall on their hind legs and 5 feet (1.5 meters) tall when on all fours.

Brown bears exhibit sexual dimorphism, with males being significantly larger than females. This size difference is a result of larger males having better mating success than smaller males.

Male bears are close to 2 times heavier than females. A typical adult male weighs between 300-850 pounds (130-390 kilograms), while the adult female weighs between 200-450 pounds (90-200 kilograms). Kodiak bears, the largest of the species, can weigh over 1,000 pounds (450 kilograms), as can those brown bears on the Alaska Peninsula as featured in episode 1 of Bears of the Last Frontier.

Fur: The coloring of brown bears differs according to environmental conditions, such as diet and temperature, which are specific to the geographical area in which they live. Their fur can be whitish, blond, red, or black, in addition to the typical dark brown.

Diet: Brown bears are apex predators, meaning they are at the top of the food chain.

Though brown bears are often perceived as carnivores, they are actually omnivorous. Depending on season, habitat, and region, they can eat grasses, berries, sedges, fungi, mosses, roots, nuts, fruits, honey, insects, birds, and fish (trout, bass, and particularly adult salmon returning to rivers to spawn). In some regions, 80-90% of their diet consists of vegetation. Bears will also hunt mammals such as rodents, mountain sheep, caribou, elk, moose, and will eat carrion, as well.

To prepare for hibernation, in the summer months bears can consume up to 90 pounds (40 kilograms) of food a day, and gain up to 3 pounds (1.3 kilograms) per day. It’s especially important that pregnant females build up their fat reserves so that they are able to nurse their young inside the den.

Habitat: Brown bears live in a variety of habitats, including forests, woodlands, alpine and subalpine meadows, and even the Arctic tundra. Following the food, they relocate depending on the seasons—living at lower elevations in the spring and higher elevations in wintertime.

Geography: Brown bears are the most widely distributed bears in the world. They are found in North America, Europe, and Asia. Two subspecies of brown bear are native to North America: the grizzly bear (U. a. horribilis) and the Kodiak bear (U. a. middendorffi). Grizzlies were once widespread throughout North America, inhabiting the Great Plains region with north/south ranges from Alaska to Mexico, and west/east ranges from California to Ohio. Now, they are found only in four U.S. mainland states: Washington, Idaho, Montana, and Wyoming where fewer than 2000 remain. Brown bears are far more numerous in the state of Alaska where there are an estimated 30,000 bears—about 95% of the entire population in the United States.

Lifespan: Brown bears typically live 20 to 25 years in the wild.

Breeding: Brown bears reach sexual maturity at an average age of 5 years. The bears locate potential mates primarily by scent, with mating season generally lasting from early May through mid-July. A female usually mates once every 2 to 4 years, and males vigorously compete for the chance to mate with her. In addition, because females mate with several males throughout the season, a male may attempt to guard a female from other males for a period of 1 to 3 weeks after mating. Unlike most mammals, female bears have delayed implantation— the fertilized egg will float in her uterus for approximately five months before implanting. Then, after a gestation period of 180-270 days, the mother gives birth in the den, usually while still hibernating. Cubs are born blind and toothless sometime between December and March, and weigh only about a pound. The sleeping mother nurses the cubs until April or May, when the hibernation period ends. Females can give birth to up to four cubs, but typically have two cubs. Cubs remain with their mothers for 2 to 4 years, during which time the mother usually does not mate. If the mother does mate, the cubs may leave to avoid any aggression from the adult male.

Hibernation: Brown bears hibernate for 5-8 months each year, beginning in the fall months. However, unlike many other hibernating mammals, brown bears do not enter true hibernation; they can wake if disturbed.

Bears hibernate in dens they dig in hillsides, choosing northward-facing slopes to ensure optimal snow cover. While hibernating, bears experience a drop in temperature and a decrease in both heart rate and metabolism. They do not excrete any waste during this time.

Social Structure: Brown bears live primarily solitary lives with the exceptions of breeding and cub rearing. Individuals typically stake out a home range. Males have areas of about 200-500 square miles (500-1300 square kilometers), though some have ranges of up to 1615 square miles (4180 square kilometers) in size. Females generally have smaller home ranges, averaging 50-300 square miles (130-780 square kilometers) in size. Though brown bears are territorial, their home ranges often overlap, and boundaries are not always enforced. They mark their range with their scent, stamping urine into the ground or rubbing their bodies against trees to leave valuable information for other bears about their size and presence.

Though social interactions are relatively rare, there is a social hierarchy in bear society; adult males are dominant, and females with cubs are dominant over young males and females without cubs.

Brown bears communicate through sound, movement, and smell. They can express emotions through a series of different vocalizations such as grunts, moans, and growls.

Conservation Status: In 1975, the Endangered Species Act listed the brown bear as a threatened species in the lower 48 States.

Threats: Logging, mining, and urban expansion results in habitat loss and a decrease in food sources. Habitat destruction also pushes brown bears into more developed areas, making conflicts with humans more likely. Human-caused mortality is the number one cause of bear population decline. Illegal hunting can be a particular problem – especially for small bear populations like those in the lower 48. The reproductive rate of brown bears is very slow, so their populations are unable to “bounce back” easily after they have been depleted.

Additional Facts:

• Brown bears have a bulky muscle mass located above the shoulders. This hump is designed to power the forelimbs and makes them exceptionally powerful diggers. This is one of the features that distinguishes them from the more common North American black bear which lacks such a shoulder hump.
• Brown bears have long claws that can be the length of a human finger. They are used for digging plant roots and excavating dens.
• Compared to black bears, brown bears have rounder, shorter ears and longer, less curved claws.
• Brown bears have keen senses of hearing and smell, but poor eyesight.
• They can run up to 35 miles per hour (or 55 km/h).
• Brown bears are very good swimmers. As cubs, they can climb trees, but as they grow larger that becomes less of an option.
• They can be active during either day or night.
• Brown bears can lose up to 40% of their body weight during hibernation.
• Brown bears are often regarded as one of the more aggressive species of bear.
• Brown bears have recently been encroaching on polar bear habitats, perhaps due to climate change.
• The grizzly’s name comes from the white-tipped, grayish, or “grizzly” furs in the bear’s coat. However, the naturalist George Ord mistook this word for “grisly,” influenced by Lewis and Clark’s description of their terrifying personal encounter with a bear, and named the subspecies horribilis.
• Polar bears are thought to have evolved from brown bears approximately 150,000 years ago.

Fortress of the Bears filmmaker Shane Moore reveals some of the filming techniques he used during his shoot on Alaska’s Admiralty Island. A behind-the-scenes look at what goes into the making of a nature documentary.

After a spring and summer with no sign of salmon, a mother bear is desperate to catch fish to feed her famished cub. Watch video.

Alaska’s Admiralty Island is home to an estimated 1800 brown bears, the largest concentration of bears in the world. Nearly 100 miles long and 20 miles wide, it is half the size of Yellowstone National Park, yet it sustains four times more grizzlies. The native Tlingít people call this island “Kootznoowoo,” meaning “Fortress of the Bears.” It is a place where bears depend on fish, fish depend on trees, and the trees depend on fish-eating bears to spread the nitrogen rich bodies of salmon throughout the forest. Everything depends on the annual salmon run. When a change in the weather keeps the salmon from arriving, the entire ecosystem is affected.

A La Niña winter has cooled the water to two degrees below normal, keeping the salmon out of the streams and delaying the run. It’s the worst salmon season in the last 40 years. As the bears wait for the salmon, they hunt and scavenge for anything they can find to supplement their unsatisfying diet of grass. The receding tide offers unique opportunities, and one young bear demonstrates a remarkable talent for clamming. But the feast is short-lived. With the passing season showing no sign of fish, the bears become increasingly gaunt and desperate. Will the salmon finally make their way up the streams of Admiralty Island? And will the bears survive until they do?

Fortress of the Bears enters a world shaped by bears, trees, and salmon, and explores the delicate balance of their interconnected lives. Fortress of the Bears premieres Wednesday, January 25 at 8/7 c.