Video above: Jack Hanna Previews AnimalsBeloved animal advocate “Jungle” Jack Hanna will retire from the Columbus Zoo and Aquarium at the end of the year. Hanna’s last day will be Dec. 31, 2020. Hanna has called the zoo home since 1978, serving as both director and director emeritus over his 42 years at the zoo. The 73-year-old is largely responsive for elevating the zoo’s reputation,