The walrus (Odobenus rosmarus) is a large flippered marine mammal with a discontinuous distribution about the North Pole in the Arctic Ocean and subarctic seas of the Northern Hemisphere. The walrus is the only living species in the Odobenidae family and Odobenus genus. This species is subdivided into three subspecies: the Atlantic walrus (O. r. rosmarus) which lives in the Atlantic Ocean, the Pacific walrus (O. r. divergens) which lives in the Pacific Ocean, and O. r. laptevi, which lives in the Laptev Sea of the Arctic Ocean. Adult walruses are easily recognized by their prominent tusks, whiskers, and bulkiness. Adult males in the Pacific can weigh more than 2,000 kg (4,400 lb) and, among pinnipeds, are exceeded in size only by the two species of elephant seals. Walruses live mostly in shallow waters above the continental shelves, spending significant amounts of their lives on the sea ice looking for benthic bivalve mollusks to eat. Walruses are relatively long-lived, social animals, and they are considered to be a "keystone species" in the Arctic marine regions. The walrus has played a prominent role in the cultures of many indigenous Arctic peoples, who have hunted the walrus for its meat, fat, skin, tusks, and bone. During the 19th century and the early 20th century, walruses were widely hunted and killed for their blubber, walrus ivory, and meat. The population of walruses dropped rapidly all around the Arctic region. Their population has rebounded somewhat since then, though the populations of Atlantic and Laptev walruses remain fragmented and at low levels compared with the time before human interference.
The bowhead whale (Balaena mysticetus) is a species of the right whale family Balaenidae, in suborder Mysticeti and genus Balaena. A stocky dark-colored whale without a dorsal fin, it can grow to 20 m (66 ft) in length. This thick-bodied species can weigh 80 to 100 tons. It lives entirely in fertile Arctic and sub-Arctic waters, unlike other whales that migrate to feed or reproduce to low latitude waters. It was also known as Greenland right whale or Arctic whale. American whalemen called it the steeple-top, polar whale, or Russian whale. The bowhead has the largest mouth of any animal. The bowhead was an early whaling target. Its population was severely reduced before a 1966 moratorium. The population is estimated to be over 24,900 worldwide, down from an estimated 50,000 before whaling.
The beluga whale or white whale (Delphinapterus leucas) is an Arctic and sub-Arctic cetacean. It is one of two members of the family Monodontidae, along with the narwhal, and the only member of the genus Delphinapterus. This marine mammal is commonly referred to simply as the melonhead, beluga or sea canary due to its high-pitched twitter. It is adapted to life in the Arctic, so has anatomical and physiological characteristics that differentiate it from other cetaceans. Amongst these are its unmistakable all-white colour and the absence of a dorsal fin. It possesses a distinctive protuberance at the front of its head which houses an echolocation organ called the melon, which in this species is large and plastic (deformable). The beluga's body size is between that of a dolphin's and a true whale’s, with males growing up to 5.5 m (18 ft) long and weighing up to 1,600 kg (3,500 lb). This whale has a stocky body; it has the greatest percentage of blubber. Its sense of hearing is highly developed and it possesses echolocation, which allows it to move about and find blowholes under sheet ice. Belugas are gregarious and they form groups of up to 10 animals on average, although during the summer months, they can gather in the hundreds or even thousands in estuaries and shallow coastal areas. They are slow swimmers, but can dive down to 700 m (2,300 ft) below the surface. They are opportunistic feeders and their diets vary according to their locations and the season. They mainly eat fish, crustaceans and other deep-sea invertebrates.
The polar bear (Ursus maritimus) is a carnivorous bear whose native range lies largely within the Arctic Circle, encompassing the Arctic Ocean, its surrounding seas and surrounding land masses. It is a large bear, approximately the same size as the omnivorous Kodiak bear (Ursus arctos). A boar (adult male) weighs around 350–700 kg (770–1,540 lb), while a sow (adult female) is about half that size. Although it is the sister species of the brown bear, it has evolved to occupy a narrower ecological niche, with many body characteristics adapted for cold temperatures, for moving across snow, ice, and open water, and for hunting the seals which make up most of its diet. Although most polar bears are born on land, they spend most of their time at sea. Their scientific name means "maritime bear", and derives from this fact. Polar bears hunt their preferred food of seals from the edge of sea ice, often living off fat reserves when no sea ice is present. The polar bear is classified as a vulnerable species, with eight of the nineteen polar bear subpopulations in decline. For decades, large scale hunting raised international concern for the future of the species but populations rebounded after controls and quotas began to take effect. For thousands of years, the polar bear has been a key figure in the material, spiritual, and cultural life of Arctic indigenous peoples, and polar bears remain important in their cultures.
The Arctic fox (Vulpes lagopus), also known as the white fox, polar fox, or snow fox, is a small fox native to the Arctic regions of the Northern Hemisphere and common throughout the Arctic tundra biome. It is well adapted to living in cold environments. It has a deep thick fur which is brown in summer and white in winter. Its body length ranges from 46 to 68 cm (18 to 27 in), with a generally rounded body shape to minimize the escape of body heat. The Arctic fox preys on any small creatures it can find, including lemmings, voles, ringed seal pups, fish, and seabirds. It will also eat carrion, berries, and seaweed. Arctic foxes form monogamous pairs during the breeding season and usually stay together in family groups of multiple generations in complex underground dens.
The harp seal or saddleback seal is a species of earless seal native to the northernmost Atlantic Ocean and parts of the Arctic Ocean. The harp seal has a silvery-gray body. Its eyes are pure black. It has black harp or wishbone-shaped markings on the back. The baby harp seal (pup) has a yellow-white coat at birth, but after three days, the coat turns white and stays white for about 12 days. Adult harp seals grow up to be 1.7 to 2.0 m (5 to 6 feet) long and weigh from 140 to 190 kg (300 to 400 pounds). Harp seals prefer to swim in the ocean, spending relatively little time on land. These are extremely social animals and they can be very noisy, as well. They will form large colonies where they spend a great deal of time. Within that loose structure, smaller groups with their own hierarchy are believed to form. Sometimes, these large groups will have to go their separate ways there. Many harp seals are able to live up to 30 years in the wild. After 12 days the mothers abandon their babies. On the ice, pups call their mothers by "bawling" and "mumble" while playing with others. Adults "growl" and "warble" to warn off others. Underwater, adults express themselves with more than 19 call types during courting and mating.
The hooded seal (Cystophora cristata) is a large phocid found only in the central and western North Atlantic, ranging from Svalbard in the east to the Gulf of St. Lawrence in the west. The seals are typically silver-grey in color, with black spots that vary in size covering most of the body. Hooded seal pups are known as "blue-backs" because their coats are blue-grey on the back with whitish bellies, though this coat is shed after 14 months of age when the pups molt. The generic name Cystophora means "bladder-bearer" in Greek, from the species' unusual sexual ornament – a peculiar inflatable bladder on the head of the adult male. This bladder hangs between the eyes and down over the upper lip in the deflated state. In addition, the hooded seal can inflate a large balloon-like sac from one of its nostrils. This is done by shutting one nostril valve and inflating a membrane, which then protrudes from the other nostril. Nursing of the pup lasts for an average of only 4 days, the shortest lactation period of any mammal, during which the pup doubles in size, gaining around 7 kg/day. This is possible because the milk that they drink has a fat content of 60%. The female pup will mature between ages 3 and 6, whereas the male pup will mature between ages 5 and 7.
The ringed seal (Pusa hispida), also known as the jar seal and as netsik or nattiq by the Inuit, is an earless seal (family: Phocidae) inhabiting the Arctic and sub-Arctic regions. The ringed seal is a relatively small seal, rarely greater than 1.5 m in length, with a distinctive patterning of dark spots surrounded by light grey rings, whence its common name. It is the most abundant and wide-ranging ice seal in the northern hemisphere: ranging throughout the Arctic Ocean, into the Bering Sea and Okhotsk Sea as far south as the northern coast of Japan in the Pacific, and throughout the North Atlantic coasts of Greenland and Scandinavia as far south as Newfoundland, and include two freshwater subspecies in northern Europe. Ringed seals are one of the primary prey of polar bears and have long been a component of the diet of indigenous people of the Arctic.
Guillemots is the common name for several species of seabird in the auk family (part of the order Charadriiformes). In British use, the term comprises two genera: Uria and Cepphus. In North America the Uria species are called "murres" and only the Cepphus species are called "guillemots". This word of French origin apparently derives from a form of the name William, cf. French: Guillaume. The two living species of Uria, together with the razorbill, dovekie and the extinct great auk, make up the tribe Alcini. They have distinctly white bellies, thicker and longer bills than Cepphus, and form very dense colonies on cliffs during the reproductive season. In July 2013, Dr Steven Portugal from the Royal Veterinary College demonstrated that when water touches the eggs, it forms into droplets rather than running off; in other words, guillemot eggs are water-repellant and self-cleaning.
The narwhal (Monodon monoceros) is a medium-sized toothed whale and possesses a large "tusk" from a protruding canine tooth. It lives year-round in the Arctic waters around Greenland, Canada, and Russia. It is one of two living species of whale in the Monodontidae family, along with the beluga whale. The narwhal males are distinguished by a long, straight, helical tusk, which is an elongated upper left canine. The narwhal was one of many species described by Carolus Linnaeus in his publication Systema Naturae in 1758. Like the beluga, narwhals are medium-sized whales. For both sexes, excluding the male's tusk, the total body size can range from 3.95 to 5.5 metres (13.0 to 18.0 feet); the males are slightly larger than the females. The average weight of an adult narwhal is 800 to 1,600 kilograms (1,800 to 3,500 pounds). At around 11 to 13 years old, the males become sexually mature; females become sexually mature at about 5 to 8 years old. Narwhals do not have a dorsal fin, and their neck vertebrae are jointed like those of other mammals, not fused as in dolphins and most whales. The narwhal, found primarily in Canadian Arctic and Greenlandic and Russian waters, is a uniquely specialized Arctic predator. In winter, it feeds on benthic prey, mostly flatfish, under dense pack ice. During the summer, narwhals mostly eat Arctic cod and Greenland halibut, with other fish such as polar cod making up the remainder of their diet. Each year, they migrate from bays into the ocean as summer comes. In the winter, the male narwhals occasionally dive up to 1,500 metres (4,900 feet) in depth, with dives lasting up to 25 minutes. Narwhals, like most toothed whales, communicate with "clicks", "whistles", and "knocks". Narwhals can live up to 50 years old. They are often killed by suffocation when the sea ice freezes over. Another cause of fatality, specifically among young whales, is starvation. The current population of the narwhal is about 75,000, so narwhals qualify for Near Threatened under the criterion of the International Union for Conservation of Nature (IUCN). Narwhals have been harvested for over a thousand years by Inuit people in northern Canada and Greenland for meat and ivory, and a regulated subsistence hunt continues.
Baleen is a filter-feeder system inside the mouths of baleen whales. The baleen system works when a whale opens its mouth underwater and the whale takes in water. The whale then pushes the water out, and animals such as krill are filtered by the baleen and remain as food source for the whale. Baleen is similar to bristles and is made of keratin, the same substance found in human fingernails and hair. Some whales, such as the bowhead whale, have longer baleen than others. Other whales, such as the gray whale, only use one side of their baleen. These baleen bristles are arranged in plates across the upper jaw of the whale. Baleen is often called whalebone and was once used for stays in men’s shirt collars and women’s corsets.
A tusk is an external extension of a tooth--almost always a canine tooth, though in elephants they are extensions of the incisors. Antlers are extensions of the skull grown by members of the deer and antelope family. They are true bone structures that usually grow in symmetrical pairs. A horn is a pointed projection on the head of various animals consisting of a covering of keratin and other proteins surrounding a core of live bone. True horns are found mainly among the families Antilocapridae (pronghorn) and Bovidae (cattle, goats, antelope etc.).
Anaurora is a natural light display in the sky (from the Latin word aurora, "sunrise" or the Roman goddess of dawn), predominantly seen in the high latitude (Arctic and Antarctic) regions. Auroras are caused by charged particles, mainly electrons and protons, entering the atmosphere from above, causing ionization and excitation of atmospheric constituents, and consequent optical emissions. (i.e. Solar and cosmic rays hit Earth’s magnetic field and cause visual displays.)
The emperor penguin (Aptenodytes forsteri) is the tallest and heaviest of all living penguin species and is endemic to Antarctica. The male and female are similar in plumage and size, reaching 122 cm (48 in) in height and weighing anywhere from 22 to 45 kg (49 to 99 lb). The dorsal side and head are black and sharply delineated from the white belly, pale-yellow breast and bright-yellow ear patches. Like all penguins it is flightless, with a streamlined body, and wings stiffened and flattened into flippers for a marine habitat. Its diet consists primarily of fish, but can also include crustaceans, such as krill, and cephalopods, such as squid. In hunting, the species can remain submerged up to 18 minutes, diving to a depth of 535 m (1,755 ft). It has several adaptations to facilitate this, including an unusually structured hemoglobin to allow it to function at low oxygen levels, solid bones to reduce barotrauma, and the ability to reduce its metabolism and shut down non-essential organ functions. The only penguin species that breeds during the Antarctic winter, emperor penguins trek 50–120 km (31–75 mi) over the ice to breeding colonies which may include thousands of individuals. The female lays a single egg, which is incubated by the male while the female returns to the sea to feed; parents subsequently take turns foraging at sea and caring for their chick in the colony. The lifespan is typically 20 years in the wild, although observations suggest that some individuals may live to 50 years of age.
The Weddell seal, Leptonychotes weddellii, is a relatively large and abundant true seal with a circumpolar distribution surrounding Antarctica. Weddell seals have the most southerly distribution of any mammal, with a habitat that extends as far south as McMurdo Sound (at 77°S). It is the only species in the genus Leptonychotes, and the only member of the Antarctic tribe of lobodontine seals to prefer in-shore habitats on shore-fast ice over free-floating pack ice. Because of its abundance, relative accessibility, and ease of approach by humans, it is the best-studied of the Antarctic seals. An estimated 800,000 individuals remain today. Weddell seal pups leave their mothers at a few months of age. In those months, they are fed by their mothers' warming and fat-rich milk. They leave when they are ready to hunt and are fat enough to survive in the harsh weather.
Krill are small crustaceans and are found in all the world's oceans. Krill are considered an important trophic level connection – near the bottom of the food chain – because they feed on phytoplankton and to a lesser extent zooplankton, converting these into a form suitable for many larger animals for whom krill makes up the largest part of their diet. In the Southern Ocean, one species, the Antarctic krill, Euphausia superba, makes up an estimated biomass of around 379,000,000 tons, more than that of humans. Of this, over half is eaten by whales, seals, penguins, squid and fish each year, and is replaced by growth and reproduction. Most krill species display large daily vertical migrations, thus providing food for predators near the surface at night and in deeper waters during the day.
The chinstrap penguin (Pygoscelis antarctica) is a species of penguin which is found in the South Sandwich Islands, Antarctica, Deception Island, the South Orkneys, South Shetland, South Georgia, Bouvet Island and Balleny. Their name derives from the narrow black band under their heads which makes it appear as if they are wearing black helmets, making them one of the most easily identified types of penguin. Other names for them are "ringed penguins", "bearded penguins", and "stonecracker penguins" due to their harsh call.
Zavodovski Island is an uninhabited volcanic island in the Traversay Islands group of the South Sandwich Islands. It lies 350 kilometres (217 mi) southeast of South Georgia Island. It is the northernmost of the South Sandwich Islands and the nearest to South Georgia. The largest concentration of chinstrap penguins is found on Zavodovski Island, comprising over 10 million penguins at certain times of the year.
Minke whale is a name given to two species of marine mammal belonging to a clade within the suborder of baleen whales. The minke whales are the second smallest baleen whale; only the pygmy right whale is smaller. Upon reaching sexual maturity (6–8 years of age), males measure an average of 6.9 m (23 ft) and females 7.4 m (24 ft) in length, respectively. Reported maximum lengths vary from 9.1 to 10.7 m (30 to 35 ft) for females and 8.8 to 9.8 m (29 to 32 ft) for males. Both sexes typically weigh 4–5 t (3.9–4.9 long tons; 4.4–5.5 short tons) at sexual maturity, and the maximum weight may be as much as 10 t (9.8 long tons; 11 short tons). The minke whale is a black/gray/purple color. Common minke whales (Northern Hemisphere variety) are distinguished from other whales by a white band on each flipper. The whale breathes three to five times at short intervals before 'deep-diving' for two to 20 minutes. Deep dives are preceded by a pronounced arching of the back. The maximum swimming speed of minkes has been estimated at 38 km/h (24 mph).
The humpback whale (Megaptera novaeangliae) is a species of baleen whale. One of the larger rorqual species, adults range in length from 12–16 metres (39–52 ft) and weigh approximately 36,000 kilograms (79,000 lb). The humpback has a distinctive body shape, with unusually long pectoral fins and a knobbly head. An acrobatic animal known for breaching and slapping the water with its tail and pectorals, it is popular with whale watchers off the coasts of Austral-asia and the Americas. Males produce a complex song lasting 10 to 20 minutes, which they repeat for hours at a time. Its purpose is not clear, though it may have a role in mating. Found in oceans and seas around the world, humpback whales typically migrate up to 25,000 kilometres (16,000 mi) each year. Humpbacks feed only in summer, in polar waters, and migrate to tropical or subtropical waters to breed and give birth in the winter. During the winter, humpbacks fast and live off their fat reserves. Their diet consists mostly of krill and small fish. Humpbacks have a diverse repertoire of feeding methods, including the bubble net feeding technique. Like other large whales, the humpback was and is a target for the whaling industry. Once hunted to the brink of extinction, its population fell by an estimated 90% before a moratorium was introduced in 1966. While stocks have since partially recovered, entanglement in fishing gear, collisions with ships, and noise pollution continue to impact the 80,000 humpbacks worldwide.
Fur seals are any of nine species of pinnipeds in the Otariidae family. One species, the northern fur seal (Callorhinus ursinus) inhabits the North Pacific, while seven species in the Arctocephalus genus are found primarily in the Southern Hemisphere. They are much more closely related to sea lions than true seals, and share with them external ears (pinnae), relatively long and muscular foreflippers, and the ability to walk on all fours. They are marked by their dense underfur, which made them a long-time object of commercial hunting.
The leopard seal (Hydrurga leptonyx), also referred to as the sea leopard, is the second largest species of seal in the Antarctic (after the southern elephant seal). It is most common in the Southern Hemisphere along the coast of Antarctica and on most sub-Antarctic islands, but can also be found on the coasts of southern Australia, Tasmania, South Africa, New Zealand, Lord Howe Island, Tierra del Fuego, the Cook Islands, and the Atlantic coast of South America. It can live 26 years, possibly more. Leopard seals are predators, feeding mainly on other seals, penguins, fish, and krill. Killer whales are the only known, albeit infrequent, natural predators of leopard seals. Along with all of the other earless seals, it belongs to the family Phocidae, and is the only species in the genus Hydrurga. The name hydrurga means "water worker" and leptonyx is the Greek for "small clawed.”