Maternal Brown Bear Adopts Abandoned Cub in Alaska Preserve

— -- The story of a brown bear’s remarkable acts of motherly kindness have earned her the nickname, “Supermom.”

The bear, named Holly, lives in Katmai National Park and Preserve in Alaska.

Park rangers said Holly took in a brown bear cub that likely would have died after he was abandoned by his own mother, who left him to run off with a male suitor. Park rangers said the cub would wait for hours at a time at the waterfall where his mother left him.

New Jersey Bear Spotted Walking on Hind Legs

Hungry Bear Pays Visit to Colorado Restaurant, Gets Meal to Go

Florida Black Bear Takes Break, Rests in Hammock

Holly noticed the cub and cared for him, and now raises him as her own.

“It is a very rare event in the bear world,” Mike Fitz, a park ranger, told ABC News. “It is really wonderful to see this so unique event.”

Holly was captured in pictures as she looked for a catch, and prepared for hibernation with her adopted son and her own 9-month-old biological cub. Hibernation is a ritual that young bears must be taught every year in order for them to survive.

This wasn’t the first time Holly’s maternal instincts kicked into overdrive. In 2007, when one of her own cubs broke a leg, she nursed him back to health and was spotted several times carrying him across a river on her back. He has been dubbed “Backpack.”

It was not clear why Holly took in the abandoned bear, Fitz said.

“It could be just a maternal instinct of the mother," he said. "The bottom line is we are not sure why she did it.”

While Katmai Park officials said they don’t interfere with the bears’ natural life cycle in the wild, they added that observing the relationship that Holly has developed with the young cub is inspiring.

“It is definitely to the cub’s advantage to be with her," Fitz said. "If it is with Holly, than he has certainly increased his chances of survival.”

You can watch the exploits of Holly and her adopted cub via live cams on explore.org and on ABCNews.com/live.