![]() It can survive for three weeks at a body temperature of 22 degrees F, a condition that would kill more southerly rodent hibernators in less than an hour.īarnes and his colleagues have found that females and yearlings of both genders exit their dens from mid-April to early May at their lowest weight of the year. The rodent endures some of the planet’s harshest winters and the shortest active season of any hibernator, as little as three months. The Arctic ground squirrel (right) probably is North America’s champion hibernator and certainly its northernmost, a circumpolar species found all the way to the Arctic Coast. Who is the Better Hibernator, Ground Squirrels or Bears? Scientists are discovering that the behavior is more complex than its basically comatose state might suggest and that it may offer pathways to treatments of human ailments such as osteoporosis. Among mammals, hibernators are found in bears, bats, rodents and even primates-at least three species of lemur in Madagascar hibernate. That helps explain why hibernation is found in a wide range of species, from mammals to snakes to fishes. Some evidence suggests that by avoiding such stresses as hunger and bad weather, hibernating species live longer than related animals that don’t hibernate. During hibernation, Barnes says, an animal can “manipulate every cell’s need for energy and oxygen plus reduce heat production,” curtailing its need for fuel when food is scarce. “Hibernation is an adaptation to an anticipation of famine,” says Brian Barnes, director of the Institute of Arctic Biology at the University of Alaska–Fairbanks, who has studied hibernation for 40 years. Sagacity is won slowly, and only in recent times have the slumbers of hibernation begun waking to the prodding of science. But he also espoused many misguided ideas about “winter hiding,” believing that migratory birds disappeared in cold seasons because they were hibernating. He reported that brown bears fatten before winter, sleep in dens in which females give birth, sometimes wake during hibernation and go the entire winter without eating-all true. by concealing themselves in warm places,” wrote the Greek natural historian Aristotle more than 2,300 years ago. ![]() Scientists studying this phenomenon are finding promise for human medical applications
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |