Last Thursday, Animal Care Coordinator Nigel Murphy went to one of the bear habitats at the Yellowstone Wildlife Sanctuary to investigate a spontaneous plume of snow. He was greeted by Bo, one of the Sanctuary's black bears, blinking at the bright sunshine for the first time since last fall.
After months of hibernation, Bo decided it was time to remove the snow covering the mouth of his den and look for some food and water. As the 11-year-old bear stretched and worked muscles that haven't been used all winter, Nigel tossed him some apples and encouraged him to go up to his exercise area, where a heaping pile of fresh vegetables and protein-rich kibble awaited, along with plenty of water.
Bo is usually the first of the Sanctuary's bears to awaken in the spring, sometimes staying out and sometimes crawling back in his den for another week or two of napping.
In the fall, wild black and grizzly bears in the greater Yellowstone ecosystem go into a state called hyperphagia, where they eat anything they can find. The layers of fat they add in the fall keep them healthy and warm all winter long. Not all bears hibernate, though. In warmer climates where food is plentiful through the winter, there's no need to fatten up and sleep through the winter.
Bo, who slept through his 11th birthday last month, is the youngest of the Sanctuary's four black bears. In the wild, a black bear can expect to live 10-18 years, but 25-30 year lifespans are not uncommon with well cared-for captive bears. The Sanctuary's oldest bears were born about 1994, and are still healthy and active.