Talk about a nice long nap.

The Birmingham Zoo’s female black bears, Bety and Sassy, had a long sleep, but now they’re up and about after 88 days in bed.

Sassy started showing the first signs of activity on Feb. 19, so keepers began getting the bear yards ready, filling up their water pools.

The bears are protective of their dens during “torpor,” or temporary hibernation, so they are kept separate. Torpor is a milder form of hibernation in which bears sleep extended periods in a kind of induced hypothermia to conserve energy with a low metabolism rate in response to colder weather.

The bears were in their dens from Nov. 29, 2023, to Feb. 25, a total of 88 days. That’s a longer winter nap than the previous year, when they slept from Oct. 26 to Jan. 10, a total of 50 days.

Turns out bear sleep is good for weight loss.

“They lost 41 pounds between the two of them,” said Bill Lang, director of marketing for the Birmingham Zoo.

Bety lost 18.1 pounds this year, more than the 12.7 pounds last year.

Sassy lost 23.3 pounds this year, up from 10.1 pounds of weight loss last year.

“They’re back, and a lot thinner,” Lang said.

They are returning to public view as a zookeeper will feed them about 1:30 p.m. today.

The bears will gradually regain their weight with their daily feedings. They will soon regain their normal energy and be back to climbing trees.