Native to the North American tundra and northern Russia, this animal burrows （打地洞）beneath the permafrost(永久冻结带)and slips into a state of suspended animation, its body temperature plummeting(急剧下降) to a frigid -2.9 degrees Celsius.
Others, like the female black bear, can multitask, giving birth and lactating(分泌乳汁) while they’re hibernating through the winter.
The fat-tailed dwarf lemur prepares for its long dormancy by gorging on food(狼吞虎咽) and storing the majority of its fat reserves in its tail, doubling its body weight. After hibernation, it emerges looking as svelte（苗条） as ever.
studies have revealed that these animals are able to turn on the genes that control fat metabolism precisely when they need to use their fat stores as fuel to survive long periods of fasting.
Understanding how hibernators deal with reduced blood flow could lead to better treatments for protecting the brain during a stroke.
Figuring out how these animals avoid muscle deterioration might improve the lives of bedridden patients.
And studying how hibernating animals control their weight with ease could illuminate the relationship between metabolism and weight gain in humans.
Hibernation is actually made up of regular bouts of reduced metabolic rate and body temperature known as torpor(迟缓).
Hibernation is a necessity, a survival tactic for making it through the harsh winter months when dwindling food and water reserves threaten survival.
For many years, experts believed hibernation happened only in arctic and temperate environments. But more recently, they’ve discovered animals hibernating even in arid deserts and tropical rainforests.
As hibernation kicks in, animals’ heartbeats usually slow to about 1 to 3% of their original speed, like the dwarf lemur’s, which drops from its usual roughly 180 beats per minute to just around four.
Breathing also declines dramatically to just one breath every 10 to 21 minutes in the lemur’s case.
And black bears, like most hibernators, don’t urinate or defecate the entire hibernation season.
Hibernating animals appear to stay alive by having just enough blood and oxygen moving around their bodies.
