The oldest hippo in America—and possibly the world—has celebrated his last Bertday. Bertie, a 58-year-old male, was euthanized at Denver Zoo yesterday after keepers noticed a steep decline in the aging animal's quality of life, the Denver Post reports.

Hippos don't usually make it much past 40 in the wild or 50 in captivity, the zoo says, and Bertie had been showing little interest in taking part in training sessions, leaving his pool, or even eating.

Bertie had been at the zoo since the Eisenhower administration, having been transferred as a 2-year-old in 1958 from New York's Central Park Zoo. The zoo had long celebrated the hippo's "Bertday" with a party in August, and at last year's celebration, a keeper noted that "58 in hippo years is like a man being 110," CBS Denver reports.

Bert had two mates over the decades and fathered a total of 29 hippos, including Mahali, a 12-year-old male who is now the zoo's only hippo.

"This is a very sad loss for Denver Zoo and our community. Bert was a member of our family for more than 50 years," the zoo's president said in a statement.

"He will be missed by all of us, including the many families and children who visited him and came to know his charismatic personality over the years." (Meanwhile, in Colombia, a drug lord's hippos are breeding out of control.)

This article originally appeared on Newser: America's Oldest Hippo Dies

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