Animal expert, Columbus Zoo director emeritus, and former legendary David Letterman guest Jack Hanna is retiring from public life following a dementia diagnosis, according to a statement from his family. In that announcement (embedded at the bottom) the family adds that it’s now believed that Hanna has contracted Alzheimer’s disease due to a faster than anticipated progression of his condition. 

“Jungle Jack” was the Columbus Zoo director from 1978 to 1992. He was still serving as its director emeritus, though it’s not clear if/how that’s been affected by this development. He was also a spokesman for the zoo, based in Ohio, until he retired last year. 

The statement released to the public was signed by his three daughters. 

“While Dad’s health has deteriorated quickly, we can assure you that his great sense of humor continues to shine through,” they wrote. “And yes, he still wears his khakis at home.”

In addition to maybe being the all-time greatest Letterman guest (93 total appearances!) Hanna also brought animals onto late shows hosted by Johnny Carson and James Corden, in addition to having some daytime program appearances on programs like The Ellen DeGeneres Show and Maury. These slots, which were always entertaining (by all means fact check that on YouTube), are said to have brought massive increases in attendance to the Columbus Zoo. 

He also hosted his own syndicated TV show, Jack Hanna’s Animal Adventures, for a 15-year stretch between 1993 and 2008. Other shows he helmed included Jack Hanna’s Into the Wild and Jack Hanna’s Wild Countdown

Due to COVID, his family has asked for privacy. 

“He has spent his life connecting people and wildlife because he has always believed that having people see and experience animals is key to engaging them in more impactful conversations,” his daughters added. “Even though Dad is no longer able to travel and work in the same way, we know that his infectious enthusiasm has touched many hearts and will continue to be his legacy.”

You can read their entire statement below: