To delete this file, click the file name with your mouse, then right-click and scroll down the menu to the "delete" option. To remove the photo permanently from the desktop, locate the photo on the hard drive and drag it to the trash.
Explore 120 years of amazing discoveries, fascinating maps, and the world's best photography.
Dutiful mothers, female polar bears usually give birth to twin cubs, which stay with her for more than two years until they can hunt and survive on their own. In winter, female polar bears give birth to two cubs in an igloo-like den, which insulates the mother and babies against the brutal winds and frigid Arctic temperatures outside.
The Arctic Ocean's sea ice is in a "death spiral" due to rising temperatures, scientists said in 2008. Polar bears—like this one leaping between ice floes in Svalbard, Norway's Hinlopen Strait—live on the Arctic ice, hunting seals and other fatty marine mammals.
Permafrost—the frozen soil that forms the backbone of the Arctic tundra—is melting due to climbing global temperatures. Thermokarst failures occur when permafrost—a layer of frozen soil in Earth's polar regions—thaws and becomes unstable, possibly releasing greenhouse gases into the atmosphere.
Freezing water from beneath Earth's surface forces the ground upward in Canada's Mackenzie River delta. Caribou—such as this large-antlered specimen silhouetted by Alaska's northern lights—are being affected as global warming accelerates in the Arctic. A forest of dead spruce trees near Homer, Alaska, is the victim of a tiny beetle that has boomed in the state's milder winters. The Inuit, a group of indigenous people living in the Arctic, are finding their land and cultures rapidly changing as climate change deepens its grip. The National Geographic Society aims to be an international leader for global conservation and environmental sustainability. Atlantic puffins spend most of their lives at sea, but return to land to form breeding colonies during spring and summer. Arctic skuas, also called parasitic jaegers, have a well-earned reputation as avian pirates, stealing much of their food from other birds. A newborn narwhal calf is about 5 feet (1.5 meters) long and can weigh 175 to 220 pounds (79 to 100 kilograms). Both male and female walruses have tusks and have been observed using these overgrown teeth to help pull themselves out of the water. Ian Stirling: At the time I wanted to do a PhD, there were few opportunities in the Canadian Arctic so, when I got a chance to go to New Zealand and do my PhD on Weddell seals in 1965, and later study fur seals and sea lions in Australia, I jumped at it. That turned out to be exceptionally good fortune because when the Canadian Wildlife Service was looking for someone to study polar bears and their relationships to seals and sea ice conditions, I was already way ahead in knowledge of ice-breeding seals.
Because of the presence of polar bears and other terrestrial predators in the Arctic, seals are much more nervous about the presence of a person on the ice and thus are difficult to approach and observe. Western Hudson Bay [in Canada] was one of the areas where I did long-term (35+ years) work on polar bears. My studies in western Hudson Bay were the first to clearly (statistically) demonstrate the negative effect of climate warming on polar bears.
I was interested in studying long-term natural environmental variation in the Arctic marine system, for which I needed long-term information on numbers, reproductive rates, survival, body condition, and so on of the bears. This is exactly what you also need for studying the effects of climate warming, so when that appeared to be a possibility, we already had a long-term database, which we then just continued.
Your most recent book, Polar Bears: A Natural History of a ?Threatened Species, highlights how polar bears survive and thrive in the sea ice environment. The late spring and early summer are of critical importance to the bears because the ringed seals are born about early April, [and] are weaned at the age of six weeks, at which time they are up to 50 percent fat and not very experienced with predators. This means seal is a huge food resource, and feeding on ringed seals in many populations probably accounts for up to about 70 percent or so of the energy the bears will require for the whole year. When breakup gets earlier, it shortens the feeding period at the most important time of the year. In other areas further north, and in the Canadian Arctic Islands, the effects of climate warming appear to be less, though there is not good long-term data for most areas. An adult male polar bear stalks a yearling cub and his family in Svalbard, Norway in June 2012. Polar bears only make a kill every four to six days at the best time of the year (late spring and early summer) and less frequently at other times.
When there are going to be long intervals of time when there will be nothing at all to eat, then the ability to eat a huge amount, digest it efficiently, and then live off it as needed is critical. No one really knows this exactly, since obviously there were no humans around to document it. We see the same sort of thing today with the brown (grizzly) bears along the northern coast of western Canada and Alaska that are seen out on the ice in early spring scavenging on seals killed by bears and apparently going hunting on their own as well. The above statement is obviously quite personal and might not be shared by everyone in the same way. The loss of any such animals from our natural environment makes us poorer in a broad philosophical sense but also in an ecological sense, because it is likely to change the overall balance that has evolved between all the species in the system.
I also think that if we don’t care about the loss of some important animals initially, then we will care less about those that follow, and that lack of caring and insensitivity is likely to increase with time to the detriment of the entire planet. The big picture importance is for the ecosystem as a whole, but the polar bear is the symbol of the system. The best sea ice is the annual ice over the relatively shallow continental shelf where biological productivity is greatest—thus there are things for the invertebrates, fish, and seals to eat. Productivity is much less over the deeper areas of the Arctic Ocean so there are far fewer seals there. Ringed seals winter under the ice and keep breathing holes open by scratching the ice with the claws of their foreflippers. Although they can make good use of scavenging on a dead whale, seal, or walrus, such windfalls are not predictable [enough] to make a living on. Some bears on land may eat things like grass, berries, or goose eggs, but while such things may help a few bears for a short period of time, it is not enough to survive upon for the year. Inuit likely learned [how to hunt seals] from watching how bears do it…standing still for long periods by a breathing hole with a spear, or using dogs to sniff out seal birth lairs. Winter travel over the ice [has become] less safe because the timing of [the] breakup, locations of weak spots, and so on.

In some areas along the northern Alaskan coast, the greater expanses of open water mean that big storms are washing away some of the land villages are built on, requiring them to be moved at great expense. Polar bears are investigative and will break things that they can get hold of, as happened with the ice-cam in the book [Polar Bears: A Natural History of a Threatened Species].
I would like people to develop an understanding of how polar bears have adapted to become so successful and comfortably at home in what, to humans at least, seems an incredibly harsh and challenging environment. In gaining that understanding, they will develop a realization of why sea ice is so critical to the survival of polar bears, and that leads to an understanding of why the loss of sea ice because of climate warming will, in time, have such a negative effect on [the] polar bear as a species.
Encourage our politicians to show global leadership in slowing and eventually stopping climate warming and, as individuals, doing what we can to reduce our individual and community carbon footprints. To dedicate 40 years of one’s life to the study of such a magnificent creature shows the man has not only a scientific interest, but a spiritual one too. National Geographic VoicesResearchers, conservationists, and others around the world share stories and commentary on the National Geographic Society's conversation platform Voices.
Society Field Inspection 2016: Gulf of CaliforniaDescribed by Jacques Cousteau as the "aquarium of the world," the Gulf of California in Mexico is threatened by coastal development, climate change, and other human activities. Support National GeographicWe've supported more than 11,000 grants to scientists and others in the field.Learn more about our work. Two years after being discovered deep in a South African cave, the 1,500 fossils excavated during the Rising Star Expedition have been identified as belonging to a previously unknown early human relative that National Geographic Explorer-in-Residence Lee Berger and team have named Homo naledi.
With at least 15 individuals of all ages and both sexes represented, the find adds an unprecedented amount of information to our understanding of early human evolution in Africa. In addition, the absence of any other animal remains or large debris in the fossil chamber strongly suggests that these non-human beings intentionally deposited their dead within this cave. BANABA ISLAND, Kiribati—Asbestos dust covers the floors of Banaba’s crumbling colonial houses, buildings, and schools. In Barrow, on the northern coast of Alaska, the sun sets at five o’clock on October 31, and the temperature typically drops into the single digits.
Elsewhere in the world people may be composing the polar bear’s epitaph, but in coastal northern Alaska the great white bears are still a part of everyday life. Native hunters still pursue their millennia-old tradition of hunting polar bears for food and fur. The bears are drawn to bone piles on land, where locals dump the remains of bowhead whales harvested for subsistence. The Arctic may be ice-free every summer in as few as 30 years, experts predict, and when ice re-forms in winter it will be thinner, and there’ll be much less of it. The polar bears’ ability to survive in a blue-water Arctic is still uncertain, but the outlook is certainly bleak. The natural reaction is to turn to the more immediate—if very much the secondary—conservation challenge for polar bears: people killing them, both for reasons of public safety and for the subsistence harvest.
If polar bears face extinction from habitat loss within the century, this thinking goes, doesn’t it make sense to stop all killing of polar bears now? In the Chukchi Sea in western Alaska, biologists find healthy polar bears producing a bumper crop of cubs. Regehr is fresh ashore from the sea ice himself, where this spring he sedated, examined, and weighed 68 polar bears (including a record-setting 1,390-pounder) before releasing them back into the wild. These add to the growing number of bears studied in the Chukchi Sea since 2008 as part of a multiyear research program to understand the ecology, distribution, and demographics of this population. Regehr’s data show that polar bears in the Chukchi appear to be as healthy as they were 20 years ago.
While many conservation-minded people in the Lower 48 assume stopping all polar bear harvesting now must be a good idea, shutting down the culturally important subsistence harvest while bears are still abundant—and increasingly visible in some populated areas—would surely backfire, Regehr believes.
What’s more, in the vast, roadless, icy vastness, hunting limits would be nearly impossible to enforce. The approach that will work for both polar bears and polar people, Regehr and others contend, is to use these next few years to lay the groundwork for the challenges ahead. The key is getting hunters, communities, and regional agencies to accept a harvest quota and to participate in its enforcement.
The data show that 58 polar bears a year can be sustainably harvested from the Chukchi population today.
FWS and its Native polar bear management partner, the Alaska Nanuuq Commission, are working together to phase in that quota over the next couple of years, building community awareness and mutual trust as they go. Today coastal Alaskan Natives have a cordial and productive relationship with their Chukotkan counterparts. In Russia, all polar bear harvesting has been illegal since 1956, though unofficial reports put the number of bears killed outside the law as high as 100 a year.
Alaska, a beautiful place where I thought residents is totally formed by polar bear, now I got there also lives human beings over there. Less ice=more open water=more photosynthesis= more food for fishes=more fish=more seals=more food for polar bears.
I like polar bear, event we don’t have them in our country but I want to help and see them in wildlife. Polar bears are an icon of the Arctic realm and an indicator of changes taking place there and globally. On Thin IceThe Arctic is warming so fast that by 2050 it may be largely ice free in summer. National Geographic VideoJoin photographer Florian Schulz as he seeks to capture a dramatic image of a polar bear. Mother black bears are notoriously protective of their cubs, who stay with their mothers for about two years.
A brown bear hunts for fish in Kodiak National Wildlife Refuge on an island off the southern coast of Alaska.
A subspecies of the larger coastal brown bear, the grizzly bear gets its name from the grayish, or grizzled, tips of its fur. The fur gives them better traction on ice, while the claws are excellent weapons for hunting. Their favorite meal is seals, but they will eat anything they can catch, even scavenging through garbage in areas where their habitat overlaps with humans. Many marine species, such as these narwhals swimming through a bay in Nunavut, Canada, depend on the ice throughout their life cycles. But as the ice vanishes, some experts predict this predator will also disappear from the Arctic by 2050.

In Alaska, the mercury may rise by 1 to 5 degrees Celsius (1.8 to 9 degrees Fahrenheit) by 2100. Though the features occur naturally in some parts of the Arctic, many scientists suspect that rising temperatures are causing more to form. Much of the basin is made up of permafrost, a layer of frozen soil in Earth's polar regions. In Greenland, caribou time their births to coincide with the blooming of tundra vegetation.
Since the mid-1970s, about 50 percent, or 1 million acres (400,000 hectares), of the Kenai Peninsula's adult spruce trees have succumbed to the spruce bark beetle. But as temperatures rise, thicker, taller shrubs are spreading throughout the region, raising the likelihood for more fires in coming years. As ice declines, so does the number of days available for Inuit to hunt for animals such as seals and walrus.
When individuals pledge to use less water in their own lives, our partners carry out restoration work in the Colorado River Basin.
In the summer though, their fur turns brown, taking up to ten weeks to change color completely. I did not originally set out to study climate warming; in fact it was not on the radar of biologists at the time. By the early 1990s, I began to think climate warming was affecting the bears and, with a colleague, published the first paper to that effect in 1993. In some areas, like western Hudson Bay and the southern Beaufort Sea, climate warming is having a negative effect on the duration of sea ice for hunting seals in the critical spring period because breakup is getting earlier.
In Western Hudson Bay, breakup is now an average of three full weeks earlier than it was only 30 years ago—that is an incredible change, and bears are lighter and reproduction is reduced because of that. For northern Russia, the loss of ice is huge but we have little information on populations. Most animals in the Arctic take on food when they can and live on it to some degree during periods of food shortage, but most, such as caribou, continue to actively feed through the winter while relying on fat for the shortfall. In areas where the ice disappears completely for several months (like Hudson Bay) they don’t feed for four to five months and pregnant females for up to eight months.
However, it appears that when we got large frozen expanses of ice with seals on them, the land bears were able to go out and scavenge on dead ones or stalk live ones. There is a great deal of variation in coat color of grizzlies, so I expect the lighter-colored ones probably were more successful so that natural selection favored them and, over the longer term, they simply became white.
However, to me, the evolution of large predators into specialized habitats anywhere in the world (like the polar bear, tiger, snow leopard, leopard seal, orca) is both a scientific marvel and a thing of exquisite beauty. Without the bear, it is no longer complete and the world as a whole no longer has a complete Arctic system as a part of a complete world ecosystem. They need to surface to breathe, so they use their breathing holes as well as natural cracks, where they are accessible to the bears. They need access each year for enough time to capture enough seals to give them the fat they need to survive. For the most part, such new technology has not been used quantitatively for scientific applications.
Posters and commenters are required to observe National Geographic's community rules and other terms of service. To learn firsthand what's going on in and around this marine treasure of global importance, the National Geographic Society sent its top scientists and officials to the region in January 2016. And the odd bear strolling through a town or village is a common sight—an increasingly common one, as climate change shrinks summer sea ice. So while the FWS currently is tackling the issue of people killing polar bears, its approach may come as a surprise.
Real-world conservation stays firmly rooted in science, but with a clear view of conditions prevailing in polar bear country. Marine Mammal Protection Act recognizes the importance of traditional, subsistence harvest and can only limit it in the direst of circumstances,” Regehr explains. A male Kodiak brown bear can rear up some 10 feet (3 meters) and, at 1,500 pounds (680 kilograms), move at speeds as high as 35 miles (56 kilometers) an hour. In this false-color image of Alaska's North Slope, taken by NASA's Terra satellite, the blue-black color shows the many ponds of meltwater that collected on the coast in July 2007. Until 2003, thermokarsts—such as this one, located about 155 miles (about 250 kilometers) north of the Arctic Circle—were unheard of in northern Alaska.
Loss of permafrost due to climate change in Canada's Northern Territories may increase runoff and sediment flowing into rivers and make some slopes more unstable and vulnerable to landslides. But as climate change causes plants to peak earlier, caribou newborns that eat the plants face tougher odds for survival. The swaths of downed trees may actually turn forests from carbon sinks to sources, according to an April 2008 study.
Tundra burning may also release more organic carbon, a greenhouse gas currently stored in the soil, into the atmosphere. Shifting winds are also reshaping ice formations used as landmarks for generations, making navigation more difficult. They toured the desert islands off the southeastern coast of the Baja Peninsula and they listened to presentations by more than a dozen experts, including several whose Baja California research is funded by the Society.
Visitors might notice a higher level of supervision here, though—armed wildlife agents patrolling on ATVs to keep polar bears from trick-or-treating the kids.
A mother bear will call to her cubs when danger is present, and is fearless when defending her offspring. For instance, when dead trees decompose, they release the greenhouse gas carbon dioxide into the atmosphere. But, as Theo Ikummaq of Canada's Nunavut Province said, "We have lived in this region for centuries and we will continue to. Nice to see there beats a heart amongst the often stoney and rigid commentary of those who are considered leaders in the field of polar bear research.

Emergency food assistance program tefap
Threat security definition business
Emergency preparedness plan policy and procedure layout
Emergency audit checklist example

Rubric: How To Survive Emp


  1. Natali
    Shovel in his pack, they declared that radical Sunni Jihadists, fighting influence two.
  2. Emrah
    Audio and visual alerts contact with.