For the ability of certain operating systems, see Hibernate (OS feature)

European Hedgehog

Hibernation is a state of inactivity and metabolic depression in animals, characterized by lower body temperature, slower breathing, and lower metabolic rate. Hibernate is a feature seen in many Operating systems where the contents of RAM is written to Non-volatile storage, such as the Hard disk (as Metabolism is the set of Chemical reactions that occur in living Organisms in order to maintain Life. Hibernation conserves energy, especially during winter. In Physics and other Sciences energy (from the Greek grc ἐνέργεια - Energeia, "activity operation" from grc ἐνεργός Hibernation may last several days, or weeks depending on species, ambient temperature, and time of year. The typical winter season for a hibernator is characterized by periods of hibernation interrupted by sporadic euthermic arousals wherein body temperature is restored to typical values. Hibernation allows animals to conserve energy during the winter when food is short. During hibernation, animals drastically lower their metabolism so as to tap energy reserves stored as body fat at a slower rate. "Adipose" redirects here For the Doctor Who monster see " Partners in Crime "

Hibernating animals

Animals that hibernate include bats, some species of ground squirrels and other rodents, mouse lemurs, the West European Hedgehog and other insectivores, monotremes and marsupials. The ground squirrels are the members of the Sciuridae most closely related to the Genus Marmota. Rodentia is an order of Mammals also known as rodents, characterised by two continuously-growing incisors in the upper and lower jaws which must The mouse lemurs are the Lemurs of the genus Microcebus. Like all other lemurs all species in this genus are native to Madagascar. The West European Hedgehog ( Erinaceus europaeus) or simply the European hedgehog, is a Hedgehog Species found throughout the Palaearctic An insectivore is a type of carnivore with a diet that consists chiefly of Insects and similar small creatures Monotremes (from the Greek monos 'single' + trema 'hole' referring to the Cloaca) are Mammals that lay eggs ( Prototheria) instead Marsupials are an Infraclass of Mammals characterized by a distinctive pouch (called the marsupium) in which females carry their young through Even some rattlesnakes, such as the Western Diamondback, are known to hibernate in caves every winter. Rattlesnakes are a group of venomous Snakes, genera Crotalus and Sistrurus. Common names: western diamondback rattlesnake Texas diamond-back more. Historically, Pliny the Elder believed that swallows hibernated, and ornithologist Gilbert White pointed to anecdotal evidence in The Natural History of Selborne that indicated as much. Gaius or Caius Plinius Secundus, ( AD 23 – August 25, AD 79 better known as Pliny the Elder, was an ancient Author The swallows and martins are a group of Passerine Birds in the family Hirundinidae which are characterised by their adaptation to aerial This article is about the 18th-century English naturalist For the 20th-century American geographer see Gilbert F Birds typically do not hibernate, instead utilizing torpor. Torpor is a (usually short-term state of decreased physiological activity in an animal usually characterized by a reduced body temperature and rate of metabolism However the Common Poorwill does hibernate. The Common Poorwill, Phalaenoptilus nuttallii, is a nocturnal Bird of the family Caprimulgidae the Nightjars It is found from British Columbia ^[1] Many experts believe that the processes of daily torpor and hibernation form a continuum. Torpor is a (usually short-term state of decreased physiological activity in an animal usually characterized by a reduced body temperature and rate of metabolism

One animal that some famously consider a hibernator is the bear, although bears do not go into "true hibernation". ^[2] During a bear's winter sleep state, the degree of metabolic depression is much less than what is observed in smaller mammals. Many prefer to use the term "denning". The bear's body temperature remains relatively stable (depressed from 37 °C to approximately 31 °C) and it can be easily aroused. In contrast, hibernating ground squirrels may have core body temperatures as low as -2 °C. Some reptile species are said to brumate, or undergo brumation, but the connection to this phenomenon with hibernation is not clear. Dormancy is a period in an organism's life cycle when growth development and (in animals physical activity is temporarily suspended

Before entering hibernation most species eat a large amount of food and store energy in fat deposits in order to survive the winter. Some species of mammals hibernate while gestating young, which are born shortly after the mother stops hibernating. Gestation is the carrying of an Embryo or Fetus inside a Female Viviparous Animal.

For a couple of generations during the 20th century it was thought that basking sharks settled to the floor of the North Sea and hibernated; however, research by Dr David Sims in 2003 dispelled this hypothesis,^[3] showing that the sharks actively traveled huge distances throughout the seasons, tracking the areas with the highest quantity of plankton. The basking shark, Cetorhinus maximus, is the second largest Fish, after the Whale shark. The North Sea is a marginal, Epeiric sea of the Atlantic Ocean on the European Continental shelf.

The epaulette sharks have been documented to be able to survive for long periods of time without oxygen, even being left high and dry, and at temperatures of up to 26 °C. The epaulette shark, Hemiscyllium ocellatum, is a bamboo shark in the family Hemiscylliidae found in the western Pacific Ocean off Papua ^[4] Other animals able to survive long periods without oxygen include the goldfish, the red-eared slider turtle, the wood frog, and the bar-headed goose. The goldfish, Carassius auratus, was one of the earliest Fish to be domesticated, and is still one of the most commonly kept aquarium fish and The Red-eared Sliders ( Trachemys scripta elegans) is a semi-aquatic Turtle ( Terrapin) belonging to the family Emydidae. Wood frog is the common name given to Rana sylvatica. The wood frog has a broad North American distribution extending from the southern Appalachians to the boreal forest The Bar-headed Goose ( Anser indicus) is a Goose which breeds in Central Asia in colonies of thousands near mountain lakes ^[5]

Until recently no primate, and no tropical mammal, was known to hibernate. A primate is a member of the biological order Primates ( Latin: "prime first rank" the group that contains Lemurs the Aye-aye The Tropics are centered on the Equator and limited in Latitude by the Tropic of Cancer in the northern hemisphere at approximately 23°26' (23 Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands However, animal physiologist Kathrin Dausmann of Philipps University of Marburg, Germany, and coworkers presented evidence in the 24 June 2004 edition of Nature that the Fat-tailed Dwarf Lemur of Madagascar hibernates in tree holes for seven months of the year. The University of Marburg (Philipps-Universität Marburg 'Philip's University Marburg' was founded in 1527 by Landgrave Philip I of Hesse (usually Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. Events 972 - Battle of Cedynia, the first documented victory of Polish forces takes place "MMIV" redirects here For the Modest Mouse album see " Baron von Bullshit Rides Again " Nature is a prominent Scientific journal, first published on 4 November 1869 The Fat-tailed Dwarf Lemur ( Cheirogaleus medius) or Lesser Dwarf Lemur, is one of the smallest Primates It is endemic to Madagascar. This is interesting because Malagasy winter temperatures sometimes rise to over 30 °C (86 °F), so hibernation is not exclusively an adaptation to low ambient temperatures. Madagascar, or Republic of Madagascar (older name Malagasy Republic) is an Island nation in the Indian Ocean off the southeastern The hibernation of this lemur is strongly dependent on the thermal behavior of its tree hole: if the hole is poorly insulated, the lemur's body temperature fluctuates widely, passively following the ambient temperature; if well insulated, the body temperature stays fairly constant and the animal undergoes regular spells of arousal. Dausmann found that hypometabolism in hibernating animals is not necessarily coupled to a low body temperature.

Noise and vibration from snowmobiles, all-terrain vehicles and the like is said to sometimes awaken hibernating animals, who may suffer severely or die as a result of premature awakening in times of food shortage.

Human hibernation

There are many research projects currently investigating how to achieve "induced hibernation" in humans. ^[6][7] The ability for humans to hibernate would be useful for a number of reasons, such as saving the lives of seriously ill or injured people by temporarily putting them in a state of hibernation until treatment can be given (compare induced coma). A barbiturate-induced coma, or barb coma, is a temporary Coma (a deep state of Unconsciousness) brought on by a controlled dose of a Barbiturate NASA is also interested in possibly putting astronauts in hibernation when going on very long space journeys, making it possible one day to visit far away stars. The National Aeronautics and Space Administration ( NASA, ˈnæsə is an agency of the United States government, responsible for the nation's public space program Interstellar space travel is unmanned or manned Travel between Stars The concept of interstellar travel in Starships is a staple in Science fiction

Erika Nordby, a toddler of 13 months in Edmonton, Alberta, wandered outside her family home on February 23, 2001. Edmonton (ˈɛdmɨntɨn is the capital of the Canadian province of Alberta. Alberta (ælˈbɝtə is one of Canada's prairie provinces. It became a province on September 1 1905 Events 1455 - Traditional date for the publication of the Gutenberg Bible, the first Western Book printed from Movable Year 2001 ( MMI) was a Common year starting on Monday according to the Gregorian calendar. The outside temperature was -24°C (-11°F). The Celsius Temperature scale was previously known as the centigrade scale. Fahrenheit is a temperature scale named after Daniel Gabriel Fahrenheit (1686–1736 a German Physicist who proposed it in 1724 When she was found, her heart had stopped beating for two hours and her internal body temperature had fallen to 16°C (61°F). Other sources say there was a slow pulse of 30 beats per minute but no blood circulation when paramedics arrived. In either event she was clinically dead. ^[8] She suffered severe frostbite, yet required no amputation and made a full recovery. Frostbite ( congelatio in Medical terminology) is the Medical condition whereby damage is caused to Skin and other tissues Amputation is the removal of a body extremity by trauma or Surgery. ^[9][10]

In October 2006, a Japanese man, Mitsutaka Uchikoshi, was believed to have been in a "denning"-like state for three weeks. For a topic outline on this subject see List of basic Japan topics. He had fallen asleep on a snowy mountain and claimed he had only woken up after being discovered 23 days later; doctors who treated him believed his internal body temperature had fallen to 22°C (71°F) during that period. ^[11]

See also

• Hibernation induction trigger
• Dormancy - a period when development is temporarily suspended
• Estivation - a state of dormancy similar to hibernation, except it is used in the summer
• Diapause - a state of metabolic dormancy that requires specific stimuli to trigger and release, which only occurs in insects. Hibernation induction trigger ( hibernation inducement trigger or HIT) is a substance found in the Blood of hibernating animals Dormancy is a period in an organism's life cycle when growth development and (in animals physical activity is temporarily suspended Estivation or aestivation (from Latin aestas, summer also known as "summer sleep" is a state of Dormancy somewhat similar Diapause is a Physiological state of Dormancy with very specific triggering and releasing conditions
• Suspended animation - also similar to hibernation, but induced artificially
• Torpor - regulated hypothermia for less than a day, often used by birds
• Sleep (non-human)

References

External links

• Hibernation on Demand
• Freeze avoidance in a Mammal: Body Temperatures Below 0 °C in an Arctic Hibernator
• Prospects for Human Hibernation: ESA Advanced Concepts Team
• Hibernation
• Human hibernation: Human hibernation project - freezing for 50 years
• Brain hibernation: Brain hibernation project