Local News Bert, The Denver Zoo's Hippo, Turns 58 August 21, 2014 / 11:43 PM MDT / CBS News Bert lived at the zoo starting at age 2. (credit: CBS) Bert, The Denver Zoo's Hippo, Turns 58 Zookeeper Dave Johnson feeds Bert some of his birthday cake. (credit: CBS) Bert, The Denver Zoo's Hippo, Turns 58 Bert eats his birthday cake, made from grains, bananas, monkey chow and apples. (credit: CBS) Bert, The Denver Zoo's Hippo, Turns 58 Bert is tame enough, zookeeper Dave Johnson says, to let him clean his teeth. (credit: CBS) Bert, The Denver Zoo's Hippo, Turns 58 The zoo has thrown Bert a public birthday celebration for the last eight years. (credit: CBS) Bert, The Denver Zoo's Hippo, Turns 58 Zoo visitors attend Bert's birthday party. (credit: CBS) Bert, The Denver Zoo's Hippo, Turns 58 Zookeeper Dave Johnson talks to the crowd about Bert, who lives with one other hippo, his son. (credit: CBS) Bert, The Denver Zoo's Hippo, Turns 58 New genetic research, zookeeper Dave Johnson says, indicates hippos are closely related to dolphins and whales. (credit: CBS) Bert, The Denver Zoo's Hippo, Turns 58 Crowds watch zookeeper Dave Johnson feed Bert. (credit: CBS) Bert, The Denver Zoo's Hippo, Turns 58 A zoo visitor signs a birthday card for Bert. (credit: CBS) Bert, The Denver Zoo's Hippo, Turns 58 Bert weighs roughly 5,000 pounds. (credit: CBS)