Jack Hanna

Jack Hanna -- the famed and beloved animal expert -- is battling with Alzheimer's disease ... and his family says it's progressed "much faster in the last few months." Jack's three daughters -- Kathaleen, Suzanne and Julie -- made the sad announcement Wednesday and said he's "no longer able to…

Legendary animal expert Jack Hanna finally has an answer to the question on everybody's mind this week ... telling us he ACTUALLY KNOWS what the fox says. Ylvis posed the question ... so we wanted an answer -- and it turns out the guys from the group were pretty close. Hanna says the animal makes…