Over the holiday weekend, Rafiki, a 31-year-old silverback gorilla at the Cheyenne Mountain Zoo, wasn’t feeling good.

On Tuesday, a zoo veterinary staff did a “full check up” and found Rafiki was suffering from severe kidney failure and gastrointestinal disease, according to a zoo media release.

Rafiki died Wednesday afternoon, the zoo said.

“The exact cause of death is still unknown,” the release said. “A full necropsy will be performed to diagnose what led to his decline in health.”

Rafiki was born at the Durrell Wildlife Conservation Trust in LaProfonde Rue, Jersey, United Kingdom, in March 1984; he also lived at the St. Louis Zoo before coming to Colorado Springs in March 2005, the zoo said.

“Rafiki was the most amazing silverback gorilla,” Dina Bredahl, animal care manager, said in the release. “He took great care of his troop, he was a playful and gentle father, and his sheer size and larger-than-life personality made such an unforgettable impression on all of us.”

Rafiki was known to visitors as “the thinker” because he often posed like the famous statue, zoo officials said. During his 10 years at the zoo, Rafiki captivated hundreds of thousands of guests.

Zoo officials let Rafiki’s troop, his fellow gorillas, “spend time with him after he passed, and each gorilla appeared to grieve for him in their own way,” the release said.

Rafiki’s 8-year-old daughter, Tumani, and his 3-year-old son, Dembe, are housed at the Cheyenne Mountain Zoo.

Kieran Nicholson: 303-954-1822, knicholson@denverpost.com or twitter.com/kierannicholson