Elias, J. S. (2007). Science Terms Made Easy: A Lexicon of Scientific Words and Their Root Language Origins. Greenwood Publishing Group. p.157. ISBN 978-0-313-33896-0.

Climate change: Polar bears could be lost by 2100 - BBC News Climate change: Polar bears could be lost by 2100 - BBC News

The pinniped ear is adapted for hearing underwater, where it can hear sound frequencies at up to 70,000 Hz. In air, hearing is somewhat reduced in pinnipeds compared to many terrestrial mammals. While they are capable of hearing a wide range of frequencies (e.g. 500 to 32,000Hz in the northern fur seal, compared to 20 to 20,000Hz in humans), their airborne hearing sensitivity is weaker overall. [54] One study of three species—the harbor seal, California sea lion and northern elephant seal—found that the sea lion was best adapted for airborne hearing, the harbor seal was equally capable of hearing in air and water, and the elephant seal was better adapted for underwater hearing. [55] Although pinnipeds have a fairly good sense of smell on land, [56] it is useless underwater as their nostrils are closed. [57] Vibrissae of walrus Underwater, pinnipeds have no sense of smell, but on land scent plays a big part in day to day life. Scent is used as an alert mechanism when predators (like humans) are nearby and as a way for males to determine whether a female is ready to mate. Scent is also an important way for mothers and pups to bond. When mothers leave their pups to forage for food they must rely on their pup’s unique scent as a way to find them among all the other pups. The walrus is the largest Arctic pinniped and the third largest of all pinnipeds (only the two species of elephant seal are larger). It grows to lengths of up to 11.81 ft. (3.6 m) and reaches weights of up to 3,432 lb. (1,557 kg).In a match-to-sample task study, a single California sea lion was able to demonstrate an understanding of symmetry, transitivity and equivalence; a second seal was unable to complete the tasks. [152] They demonstrate the ability to understand simple syntax and commands when taught an artificial sign language, though they only rarely used the signs semantically or logically. [153] In 2011, a captive California sea lion named Ronan was recorded bobbing its head in synchrony to musical rhythms. This "rhythmic entrainment" was previously seen only in humans, parrots and other birds possessing vocal mimicry. [154] Adult male elephant seals appear to memorize both the rhythm and timbre of their rivals' calls. [155] In 1971, a captive harbor seal named Hoover was trained to imitate human words, phrases and laughter. [156] Climate may also change the types of food available to pinnipeds. Galapagos sea lions historically ate sardines as the main source of their diet. But as climate change has gradually warmed the region, these fish have become scarce. During El Nino years when the water is particularly warm, up to 100 percent of newborn pups and up to 50 percent of yearlings die due to starvation. As a result, over the last 30 years the Galapagos sea lion population has shrunk from 40,000 individuals to fewer than 15,000. Without an abundant source of sardines, sea lions have had to get creative when it comes to finding food. In recent years they have been observed working in teams to corral and catch yellowfin tuna. Tuna swim about twice as fast as sea lions and so the sea lions have learned to use the maze-like shoreline to trap the fish. The entire endeavor takes time and energy, but when successfully executed, a 50-pound meal is quite the reward.

Autoglym | Polar Seal

The Caribbean monk seal has been killed and exploited by Europeans settlers and their descendants since 1494, starting with Christopher Columbus himself. The seals were easy targets for organized sealers, fishermen, turtle hunters and buccaneers because they evolved with little pressure from terrestrial predators and were thus " genetically tame". In the Bahamas, as many as 100 seals were slaughtered in one night. In the mid-nineteenth century, the species was thought to have gone extinct until a small colony was found near the Yucatán Peninsula in 1886. Seal killings continued, and the last reliable report of the animal alive was in 1952. The IUCN declared it extinct in 1996. [176] The Japanese sea lion was common around the Japanese islands, but overexploitation and competition from fisheries drastically decreased the population in the 1930s. The last recorded individual was a juvenile in 1974. [177] Conservation issues [ edit ] Lek systems are known to exist among some populations of walruses. [114] These males cluster around females and try to attract them with elaborate courtship displays and vocalizations. [114] [119] Lekking may also exist among California sea lions, South American fur seals, New Zealand sea lions and harbor seals. [114] [120] In some species, including elephant seals and grey seals, males will try to lay claim to the desired females and defend them from rivals [114] via having harems, [121] or claiming a cluster of females whose members may change over time. [122] Some male walruses guard access to female herds. [114] Male harp seals, crabeater seals and hooded seals follow and defend lactating females in their vicinity—usually one or two at a time, [123] and wait for them to reach estrus. [113] [114] Younger or subdominant male pinnipeds may attempt to achieve reproductive success in other ways including being sneaky, harassment of females or even coordinated disruption of the colony. [124] Although seals spend most of their lives in the water, they regularly come onto land; a process known as ‘ hauling out’. A structure consisting of a blood vessel that splits up into a great number of smaller vessels that run in parallel and eventually reunite into one vessel.

Seals, together with sea lions and walruses, are members of a group of animals known as Pinnipedia. Members of this group are known as pinnipeds. Seal Families Rybczynski, N.; Dawson, M. R.; Tedford, R. H. (2009). "A semi-aquatic Arctic mammalian carnivore from the Miocene epoch and origin of Pinnipedia". Nature. 458 (7241): 1021–24. Bibcode: 2009Natur.458.1021R. doi: 10.1038/nature07985. PMID 19396145. S2CID 4371413. a b Fish, F. E. (2003). "Maneuverability by the sea lion Zalophus californianus: Turning performance of an unstable body design". Journal of Experimental Biology. 206 (4): 667–74. doi: 10.1242/jeb.00144. PMID 12517984. Arnason, U.; Gullberg, A.; Janke, A.; Kullberg, M. (2007). "Mitogenomic analyses of caniform relationships". Molecular Phylogenetics and Evolution. 45 (3): 863–74. doi: 10.1016/j.ympev.2007.06.019. PMID 17919938.

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Cappozzo, H. L. (2001). "New perspectives on the behavioural ecology of pinnipeds". In Evans, P. G.; Raga, J. A. (eds.). Marine Mammals: Biology and Conservation. Kluwer Academic/Plenum Publishers. p.243. ISBN 978-0-306-46573-4. Pinnipeds that live in the sea must rely on freshwater to survive. Special adaptations help them retain as much freshwater as possible. Most freshwater comes from a pinniped’s meal—Harbor seals obtain about 90 percent of their freshwater from the fish they eat. Once the food is ingested, pinnipeds retain the water for as long as possible. Pinniped kidneys are especially efficient at retaining water, therefore, pinniped urine can be saltier than the surrounding seawater. Staying Warm Term that differs among disciplines; here an evolutionary process by which an organism becomes fitted to its environment. Endangered Salmon Predation Prevention Act". Northwest Regional Office, National Oceanic and Atmospheric Administration. 26 July 2012. Archived from the original on 15 October 2011 . Retrieved 9 June 2012.

List Of Seals That Live in the Arctic

Sea level rise could also greatly endanger pinnipeds, especially those in warmer waters. Hawaiian monk seals, for example, rely heavily on the atolls of the Northwest Hawaiian Islands, some of which only rise a few feet above current sea level and may become completely submerged if sea levels continue to rise. In the Mediterranean, monk seals inhabit coastal caves that may become increasingly flooded with rising sea levels. Captivity Seals are among the few animals able to survive on the frozen coastlines and continuously expanding and contracting sea ice of the Arctic. What Is A Seal? Boness, D. J.; Anderson, S. S.; Cox, C. R. (1982). "Functions of female aggression during the pupping and mating season of grey seals, Halichoerus grypus (Fabricius)". Canadian Journal of Zoology. 60 (10): 2270–2278. doi: 10.1139/z82-293.

Seals, Sea Lions, and Walruses | Smithsonian Ocean Seals, Sea Lions, and Walruses | Smithsonian Ocean

One popular hypothesis suggested that pinnipeds are diphyletic (descended from two ancestral lines), with walruses and otariids sharing a recent common ancestor with bears and phocids sharing one with Musteloidea. However, morphological and molecular evidence support a monophyletic origin. [14] A 2021 genetic study found that pinnipeds are more closely related to musteloids. [19] Pinnipeds split from other caniforms 50million years ago ( mya) during the Eocene. [20] Their evolutionary link to terrestrial mammals was unknown until the 2007 discovery of Puijila in early Miocene deposits in Nunavut, Canada. Like a modern otter, Puijila had a long tail, short limbs and webbed feet instead of flippers. However, its limbs and shoulders were more robust and Puijila likely had been a quadrupedal swimmer—retaining a form of aquatic locomotion that gave rise to the major swimming types employed by modern pinnipeds. The researchers who found Puijila placed it in a clade with Potamotherium (traditionally considered a mustelid) and Enaliarctos. Of the three, Puijila was the least specialized for aquatic life. The discovery of Puijila in a lake deposit suggests that pinniped evolution went through a freshwater transitional phase. [21] Fossil of Enaliarctos Despite their size and bulk, polar bears are excellent swimmers, and have been spotted in waters over 100km offshore. They can comfortably swim at around 10km/h using their slightly webbed, 30cm wide paws like paddles in the water.The primary predators of the walrus are the polar bear and the killer whale. The walrus, however, is a strong and well-armed opponent. Examples of a walrus turning the tables on a polar bear and fatally wounding the aggressor are known. It is usually only walrus calves that are targeted by predators. Miller, A. J. "Ocean Climate Changes and the Steller Sea Lion Decline" (PDF). NSF.gov . Retrieved 30 August 2013.