The Northern Lights Wildlife Shelter in Smithers was alerted to the cub's whereabouts on Sunday, after the tiny bear was seen on a farm in the village of Midway.
Angelika Langen, who works with the shelter, says of the 23 years she's been rescuing animals, this was a first.
"Usually they break into the chick coop and eat the chickens...not eat with the chickens," said Langen.
It is thought the bear, now named Tinsel, had been living in the coop for close to five days and when he arrived at the shelter on Christmas Eve, he was severely undernourished.
The 10-month-old cub should have weighed close to 30 kilograms, but instead weighed less than 10.
Langen says it's likely the bear was alone and without its mother for at least two to three months.
"They're very good at finding each other again, so I'm more inclined to think something happened to the mother."
Langen says Tinsel is making a good recovery, starting with a special Christmas dinner.
"Porridge made with water and some honey. He loved it. Dove right into it and licked it all up!"