Hibernation

related topics
{specie, animal, plant}
{disease, patient, cell}
{math, energy, light}
{day, year, event}
{island, water, area}
{water, park, boat}
{service, military, aircraft}
{car, race, vehicle}

Hibernation is a state of inactivity and metabolic depression in animals, characterized by lower body temperature, slower breathing, and lower metabolic rate. Hibernating animals conserve food, especially during winter when food supplies are limited, tapping energy reserves, body fat, at a slow rate. It is the animal's slowed metabolic rate which leads to a reduction in body temperature and not the other way around.

Hibernation may last several days or weeks depending on species, ambient temperature, and time of year, and fur on the animal's body. 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 levels. There is a hypothesis that hibernators build a need for sleep during hibernation more slowly than normally, and must occasionally warm up in order to eat. This has been supported by some evidence in the arctic ground squirrel.[1]

Contents

Hibernating animals

Animals that hibernate include bats, some species of ground squirrels and other rodents, mouse lemurs, the European Hedgehog and other insectivores, monotremes and marsupials. Even some rattlesnakes, such as the Western Diamondback, are known to hibernate in caves every summer. Historically, Pliny the Elder believed swallows hibernated, and ornithologist Gilbert White pointed to anecdotal evidence in The Natural History of Selborne that indicated as much. Birds typically do not hibernate, instead utilizing torpor. However the Common Poorwill does hibernate.[2] Many experts believe that the processes of daily torpor and hibernation form a continuum.[citation needed] Some reptile species are said to brumate, or undergo brumation, but the connection to this phenomenon with hibernation is not clear. Hibernating animals get their energy by burning fat, and are able to convert fatty acid carbons to glucose via gluconeogenesis.[3]

One animal that is famously considered a hibernator is the bear, although bears do not go into "true hibernation".[4] During a bear's winter sleep state, the degree of metabolic depression is much less than that observed in smaller mammals, the bear's body temperature remains relatively stable (depressed from 37 °C (99 °F) to approximately 31 °C (88 °F)), and it can be relatively easily aroused. Many prefer to use the term "denning" or "winter lethargy" but others just consider it a different form of hibernation.[5]

Full article ▸

related documents
Coprophagia
Embryo
Chronobiology
Gene knockout
Ossicles
Candiru
Kitten
Trypanosome
Intracytoplasmic sperm injection
Datura
Microbat
Nocturnality
Eryngium
Southern Boobook
Nautilus
Salsify
Insectivora
Penstemon
Munchkin (cat)
Apomixis
Brolga
Bullhead sharks
Common Swift
Mylodon
Dahlia
Senecio
Syringa
Himalayan Tahr
Eastern Imperial Eagle
Genipa