Gus, the Central Park Zoo's beloved polar bear, died Tuesday at age 27.
Gus was euthanized under anesthesia by Wildlife Conservation Society veterinarians after a large, inoperable tumor was found in his thyroid.
Before the procedure, Gus began exhibiting abnormal feeding behavior, with low appetite and difficulty eating. A necropsy will be conducted to determine the full extent of his condition.
Gus was born in 1985 at the Toledo Zoo before coming to the Central Park Zoo in 1988. The zoo estimates more than 20 million people visited him during his time there.
"Gus was an icon at the Central Park Zoo and a great source of joy for our visitors and staff," Jim Breheny, the Wildlife Conservation Society's executive vice president of zoos and aquarium, said in his obituary.
Gus became a national sensation in 1994 for his repetitive swimming patterns. Enrichment programs were designed for Gus, and he often foraged for his own food while in captivity.
Breheny said Gus was an "ambassador" for a species facing life-threatening problems in a changing environment.
"Polar bears are apex predators – the kings of their domain, but vulnerable in a world affected by climate change brought on by human activity," Breheny said.
The median life expectancy for male polar bears in zoos is about 21 years, the Association of Zoos and Aquariums reports.
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