HomeBlogBlack Bear Year in Shenandoah National Park: What Happens in the Winter?

Black Bear Year in Shenandoah National Park: What Happens in the Winter?

Black Bear cub eating.

by Patressa Kearns

Let’s go ahead and admit it: in one way or another, most of us are card-carrying members of the black bear fan club.

We yearn to catch a glimpse of a black bear along Skyline Drive. We can’t wait to spot a cub or two (or three!) scampering across the road and up a tree. Naturally, then, we’re curious about what happens to bears in winter when it comes time for them to hibernate.

Where do black bears go in winter? What happens to them during hibernation? And when do bears come out of hibernation and start roaming the hills and hollows of Shenandoah again?

When leaves fall from the trees and the air turns cool, black bears begin to make their way into winter dens. But a black bear starts preparing for winter hibernation weeks before it actually dens up. Because black bears do not eat or drink (they also don’t defecate or urinate) during hibernation, they must put on weight – lots of body fat – in order to survive it. When you see a black bear in August, it’s likely searching for high-calorie snacks – acorns, nuts, berries, grubs, even honey – to add weight to its frame. Come the downhill side of summer, bears know it’s time to fatten up. If there are enough acorns available, a male bear can pack on 100 pounds in one week!

But where, exactly, does a black bear go to hibernate? All kinds of places!

 

 

  • Hollow trees, either standing or on the ground, are favorite denning places for black bears.
  • Rock overhangs and caves make great bear dens.
  • Bears will often dig into hillsides or under the roots of big trees for dens. Bears begin making dens in hillsides and roots in the summer months, long before they’re ready to hibernate.
  • Hollows created by roots of dead and down trees provide great nooks for bears to den in.
  • Brush piles and piles of leaf litter work, too.
  • Some bears just rake up a bed on the ground near a windbreak and hibernate there.

Sleeping – hibernating – is how animals like black bears adapt to the dearth of nuts, berries, and grubs that winter brings; animals hibernate because of the shortage of food, not to survive the cold. Black bears hibernate in Shenandoah, then, when their natural food is in short supply – beginning in October and November. But if there is plenty of food available – a plentiful acorn crop, say, or an abundance of berries or nuts – bears may not den up at all and may continue to forage for food all winter. Some bears might even venture out of their dens and mosey around (albeit groggily) when winter temperatures run mild.

During hibernation, a black bear conserves energy by several methods. Its breathing slows down – to about one breath every 45 seconds – as does its heartbeat – to about 8 beats per minute. The extra fat the bear stored up in summer keeps it alive until spring. In fact, a bear will lose 15 to 30 percent of its body weight during hibernation. Females give birth to cubs around February and nurse them in the den.

Bears emerge from dens in late March and April – on the move again, looking for nutritious things to eat. Male bears come out first, then females with cubs. When a bear first leaves its den, it might look terribly thin, even unhealthy. But it will quickly fatten up on fiddle-head ferns, plant shoots, oak catkins, new grasses.

And the black bear year will start all over again.