Tucson’s Reid Park Zoo said “goodbye” to one of its animals Wednesday when the organization announced the passing of Shombay the African lion. Shombay lived to 12 and was diagnosed with polycystic kidney disease in 2016.

“Losing Shombay is particularly difficult for our team,” said Dr. Sue Tygielski, Director of Zoo Operations, in the zoo’s announcement. “Our animal care and veterinary teams worked so hard to encourage him to participate in training sessions to help save his life. When he received these additional fluids, he would act more energetic. The team could see clear evidence of how their skills and dedication helped Shombay. They are all proud to have worked with him and our zoo is so lucky to have such dedicated staff.”

According to the zoo, the lion’s recent blood tests showed a decline in kidney function, and “he was not participating in fluid sessions.”

“These factors combined contributed to the zoo’s decision to humanely euthanize him on Wednesday morning,” the zoo stated.

Shombay landed at Reid Park Zoo in 2010, when he was 2 years old. Known as a cautious lion, Shomby was well known for investigating new habitats before making himself comfortable—and longtime patrons may remember the mohawk he once sported in his youth.

Shombay and Kaya, a female lion at the zoo, were responsible for the birth of several litters of cubs. Their 6-year-old, Nayo, lives at Reid Park.

“We expect their behaviors to be different in the near future as they adapt to life without Shombay,” Animal Care Supervisor Rebecca Edwards said. “Our team will do all we can to make the transition as easy as possible.”