06/05/2013 09:45 EDT | Updated 08/05/2013 05:12 EDT

Smithers wildlife shelter begins bear release

A wildlife shelter in northern B.C. has begun releasing 32 bears back into the wild in one of the largest rehabilitations the shelter has undertaken.

The 29 black bears and three grizzly bears come from areas throughout the province, including Prince George, Fort St. James, Merritt and Kamloops.

They spent the winter at the Northern Lights Wildlife Shelter in Smithers, and will be released back into their natural home range this spring.

Shelter manager Angelika Langen says rescued bear cubs must achieve a good weight and be able to climb well before they are ready to be released.

"It's a defence against predators, so a bear that can't get off the ground and up the tree is not releasable. They need to be able to get up the tree like it's nothing to them," she said.

Langen says tracking collars aren't put on the black bears, so there's no way of knowing how well they do after being released in the wild, but she says studies show re-habilitated bears tend to have good survival rates.

Grizzly bears are tracked, and have so far done very well.

Regardless, Langen says every goodbye is bittersweet.

"We know that not all of them survive. But by the time that they go, they're very destructive in the enclosures because they want to get out, they're getting very cranky. And that makes it a lot easier to let them go," she said.

There are nine bears left to relocate.