Yellow-Bellied Marmot Sleeping Habits Offer Clues to Longevity

Every April, in the mountainous forests of Colorado, a fuzzy creature with a belly the color of buttered toast emerges from its snow-covered burrow. For the past eight months, the yellow-bellied marmot has been hibernating, existing in suspended animation to survive the bitterly cold winter. Although months have passed, the marmot is the same age — biologically speaking — as when it entered its den in early fall, a new study has found.