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Polar Bear
The polar bear (''Ursus maritimus'') is a large bear native to the Arctic and nearby areas. It is closely related to the brown bear, and the two species can Hybrid (biology), interbreed. The polar bear is the largest extant species of bear and land carnivore, with adult males weighing . The species is sexually dimorphic, as adult females are much smaller. The polar bear is white- or yellowish-furred with black skin and a thick layer of fat. It is more slender than the brown bear, with a narrower skull, longer neck and lower shoulder hump. Its teeth are sharper and more adapted to cutting meat. The paws are large and allow the bear to walk on ice and paddle in the water. Polar bears are both terrestrial and Pagophily, pagophilic (ice-living) and are considered marine mammals because of their dependence on marine ecosystems. They prefer the annual sea ice but live on land when the ice melts in the summer. They are mostly carnivorous and specialized for preying on pinniped, se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maternity Den
In the animal, animal kingdom, a maternity den is a lair where a mother gives birth and nurtures her young when they are in a vulnerable biological life cycle, life stage. While dens are typically subterranea (geography), subterranean, they may also be snow caves or simply beneath rock ledges. Characteristically there is an entrance, and optionally an exit corridor, in addition to a principal chamber. Examples Polar bear The polar bear (''Ursus maritimus'') creates a maternity den either in an earthen subterranean or in a snow cave. On the Hudson Bay Plain in Manitoba, Canada, many of these subterranean dens are situated in the Wapusk National Park, from which bears migrate to the Hudson Bay when the Drift ice, ice pack forms. The maternity den is the bear's shelter for most of the winter. Wild dogs Pack members may guard the maternity den used by the alpha female; such is the case with the African wild dog, ''Lycaon pictus''. Brown hyena The brown hyena (''Parahyaena ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Mammal
Marine mammals are mammals that rely on marine ecosystems for their existence. They include animals such as cetaceans, pinnipeds, sirenians, sea otters and polar bears. They are an informal group, unified only by their reliance on marine environments for feeding and survival. Marine mammal adaptation to an aquatic lifestyle varies considerably between species. Both cetaceans and sirenians are fully aquatic and therefore are obligate water dwellers. Pinnipeds are semiaquatic; they spend the majority of their time in the water but need to return to land for important activities such as mating, breeding in the wild, breeding and molting. Sea otters tend to live in kelp forests and estuaries. In contrast, the polar bear is mostly terrestrial and only go into the water on occasions of necessity, and are thus much less adapted to aquatic living. The diets of marine mammals vary considerably as well; some eat zooplankton, others eat fish, squid, shellfish, or seagrass, and a few eat ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Pleistocene
The Late Pleistocene is an unofficial Age (geology), age in the international geologic timescale in chronostratigraphy, also known as the Upper Pleistocene from a Stratigraphy, stratigraphic perspective. It is intended to be the fourth division of the Pleistocene Epoch within the ongoing Quaternary Period. It is currently defined as the time between 129,000 and c. 11,700 years ago. The late Pleistocene equates to the proposed Tarantian Age of the geologic time scale, preceded by the officially ratified Chibanian (commonly known as the Middle Pleistocene). The beginning of the Late Pleistocene is the transition between the end of the Penultimate Glacial Period and the beginning of the Last Interglacial around 130,000 years ago (corresponding with the beginning of Marine Isotope Stage 5). The Late Pleistocene ends with the termination of the Younger Dryas, some 10th millennium BC, 11,700 years ago when the Holocene Epoch began. The term Upper Pleistocene is currently in use as a p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norsemen
The Norsemen (or Northmen) were a cultural group in the Early Middle Ages, originating among speakers of Old Norse in Scandinavia. During the late eighth century, Scandinavians embarked on a Viking expansion, large-scale expansion in all directions, giving rise to the Viking Age. In English-language scholarship since the 19th century, Norse seafaring traders, settlers and warriors have commonly been referred to as Vikings. Historians of Anglo-Saxon England often use the term "Norse" in a different sense, distinguishing between Norse Vikings (Norsemen) from Norway, who mainly invaded and occupied the islands north and north-west of Britain as well as Ireland and western Britain, and Danish Vikings, who principally invaded and occupied eastern Britain. History of the terms ''Norseman'' and ''Northman'' The word ''Norseman'' first appears in English during the early 19th century: the earliest attestation given in the third edition of the ''Oxford English Dictionary'' is from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenland
Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenland are full Danish nationality law, citizens of Denmark and European Union citizenship, of the European Union. Greenland is one of the Special territories of members of the European Economic Area#Overseas countries and territories, Overseas Countries and Territories of the European Union and is part of the Council of Europe. It is the List of islands by area, world's largest island, and lies between the Arctic Ocean, Arctic and Atlantic oceans, east of the Arctic Archipelago, Canadian Arctic Archipelago. It is the location of the northernmost point of land in the world; Kaffeklubben Island off the northern coast is the world's Northernmost point of land, northernmost undisputed point of land—Cape Morris Jesup on the mainland was thought to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Pennant
Thomas Pennant (16 December 1798) was a Welsh natural history, naturalist, traveller, writer and antiquarian. He was born and lived his whole life at his family estate, Downing Hall, near Whitford, Flintshire, in Wales. As a naturalist he had a great curiosity, observing the geography, geology, plants, animals, birds, reptiles, amphibians, and fish around him and recording what he saw and heard about. He wrote acclaimed books including ''British Zoology'', the ''History of Quadrupeds'', ''Arctic Zoology'' and ''Indian Zoology'' although he never travelled further afield than continental Europe. He knew and maintained correspondence with many of the scientific figures of his day. His books influenced the writings of Samuel Johnson. As an antiquarian, he amassed a considerable collection of art and other works, largely selected for their scientific interest. Many of these works are now housed at the National Library of Wales. As a traveller he visited Scotland and many other par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circus
A circus is a company of performers who put on diverse entertainment shows that may include clowns, acrobats, trained animals, trapeze acts, musicians, dancers, hoopers, tightrope walkers, jugglers, magicians, ventriloquists, and unicyclists as well as other object manipulation and stunt-oriented artists. The term "circus" also describes the field of performance, training, and community which has followed various formats through its 250-year modern history. Although not the inventor of the medium, Newcastle-under-Lyme born Philip Astley is credited as the father of the modern circus. In 1768, Astley, a skilled equestrian, began performing exhibitions of trick horse riding in an open field called Ha'penny Hatch on the south side of the Thames River, England. In 1770, he hired acrobats, tightrope walkers, jugglers, and a clown to fill in the pauses between the equestrian demonstrations and thus chanced on the format which was later named a "circus". Performances deve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circumpolar Peoples
Circumpolar peoples and Arctic peoples are umbrella terms for the various indigenous peoples of the Arctic region. Approximately four million people are resident in the Arctic, among which 10 percent are indigenous peoples belonging to a vast number of distinct communities. They represent a minority with the exception of Greenland of which 90 percent of its population is composed of Inuit. It is difficult to find an exact number of the indigenous peoples in the Arctic as states have a tendency to downplay the numbers. Moreover, each state has its own different methods to count its indigenous population. For instance, Russia excludes from the official status of "small peoples of the North" ( or ) every community that exceeds 50,000 people. They are therefore excluding from the definition certain numerically large indigenous communities like the Komi peoples, Karelians or Yakuts. Prehistory The earliest inhabitants of North America's central and eastern Arctic are referred to as t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctic Sea Ice Decline
Sea ice in the Arctic region has declined in recent decades in area and volume due to climate change. It has been melting more in summer than it refreezes in winter. Global warming, caused by Radiative forcing#Forcing due to changes in atmospheric gases, greenhouse gas forcing is responsible for the decline in Arctic sea ice. The decline of sea ice in the Arctic has been accelerating during the early twenty-first century, with a decline rate of 4.7% per decade (it has declined over 50% since the first satellite records). Summertime sea ice will likely cease to exist sometime during the 21st century. The region is at its warmest in at least 4,000 years. Furthermore, the Arctic-wide melt season has lengthened at a rate of five days per decade (from 1979 to 2013), dominated by a later autumn freeze-up. The IPCC Sixth Assessment Report (2021) stated that Arctic sea ice area will likely drop below 1 million km2 in at least some Septembers before 2050.Fox-Kemper, B., H.T. Hewitt, C. Xia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climate Change
Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in a broader sense also includes previous long-term changes to Earth's climate. The current rise in global temperatures is Scientific consensus on climate change, driven by human activities, especially fossil fuel burning since the Industrial Revolution. Fossil fuel use, Deforestation and climate change, deforestation, and some Greenhouse gas emissions from agriculture, agricultural and Environmental impact of concrete, industrial practices release greenhouse gases. These gases greenhouse effect, absorb some of the heat that the Earth Thermal radiation, radiates after it warms from sunlight, warming the lower atmosphere. Carbon dioxide, the primary gas driving global warming, Carbon dioxide in Earth's atmosphere, has increased in concentratio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Union For Conservation Of Nature
The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status of the natural world and the measures needed to safeguard it. It is involved in data gathering and analysis, research, field projects, advocacy, and education. IUCN's mission is to "influence, encourage and assist societies throughout the world to conserve nature and to ensure that any use of natural resources is equitable and ecologically sustainable". Over the past decades, IUCN has widened its focus beyond conservation ecology and now incorporates issues related to sustainable development in its projects. IUCN does not itself aim to mobilize the public in support of nature conservation. It tries to influence the actions of governments, business and other stakeholders by providing information and advice and through building partners ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
