SAN FRANCISCO—Uulu, the beloved polar bear at the San Francisco Zoo passed away on Friday, April 14. At 36 years old, she was one of the oldest living polar bears in captivity.

Uulu was the focus of several behavioral studies and was featured in a published paper about aging animal care at the San Francisco Zoo. She was one of the oldest polar bears in any zoo that is part of the Association of Zoos & Aquariums; which promotes the welfare of animals, conservation and science.

She was the center of attention on “snow days” at the SF Zoo. Two times throughout 2016, 10 tons of snow were blown into her habitat as a treat. Over 6,000 visitors watched her roll and slide around in joy in the snow. In February, she frolicked in more snow and ice brought to her to celebrate International Polar Bear Day.

Uulu was rescued by the zoo when she was about 3 years-old from Churchill, Manitoba, Canada. Uulu, her siblings, and mom were “problem” bears. They were caught on multiple occasions foraging at the dump and even attempted to get into a home.

She experienced a rapid decline in her health after undergoing congestive heart failure and her growing age. Uulu was the only polar bear at the SF Zoo, and lived alone since, Pike, another female polar bear, died 2 years ago at the age of 32.