Watch Polar Bear Mom Nuzzle Her Tiny Newborn Cub

Congratulations are due for Crystal the polar bear.

Congratulations are due for Crystal the polar bear.

The mom, who already has twins, gave birth at the Toledo Zoo to a tiny cub.

Read: Zoo Is Hand-Rearing an Adorable Polar Bear Cub After Mother Rejected Her

Although the zoo announced the arrival of their newest cub on Thursday, the birth actually happened in a secluded den on December 3, 2015.

The mother and cub will remain secluded in the den, as they would in the wild. Instead, workers are observing their progress through a monitor.

Newly released video from the monitor shows the 16-year-old mom snuggling and nuzzling her newest addition, who has yet to be named.

Watch: Rare Black Rhino Takes His First Steps Just Moments After Being Born

“We are very excited about the successful birth and rearing of this cub," said Dr. Rani Meyerson, assistant director of animal programs.

"Crystal has always demonstrated great maternal care. The cub still has a lot of important milestones [to achieve] before going on exhibit, but we are cautiously optimistic that both mom and cub will continue to thrive."

The two bears will stay in the den until the cub has substantially grown so the sex of the cub will remain unknown. A date for the duo to enter a public exhibit still hasn’t been determined.   

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