An Oregon zoo euthanized one of the world's oldest penguins: 'It was hard for him to see, and at times difficult for him to walk'

• The Oregon Zoo in Portland says it had to euthanize a Humboldt penguin named Mochica over the weekend.
• Mochica was 31 years old, and believed to be one of the oldest penguins in the world.
• The zoo said Mochica had to be euthanized because of age-related ailments.

One of the oldest Humboldt penguins in the world had to be euthanized over the weekend at the Oregon Zoo.

The zoo said on its website that Mochica, also known as Mo, was euthanized on Saturday at 31 years old because of age-related ailments.

"He had a mature cataract in one eye, old-age haze in the other, bilateral arthritis in his hips," Travis Koons, who oversees the zoo's bird populations, said on the zoo's website. "He was just a very old bird. It was hard for him to see, and at times difficult for him to walk."

Mochica was born on July 6, 1990, at the Oregon Zoo in Portland, where he lived his entire life.

"Mochica was the oldest male of his species in any North American zoo or aquarium, maybe the whole world," Koons added in later press release shared with Insider. "His remarkable longevity says a lot about both his zest for life and the quality of care he received over the years."

According to the news release, Humboldt penguins rarely live past 20 years old.

"It's an incredibly sad day for his care team and for everyone who spent time with this amazing bird," Koons said. "We've all had times in our lives where animals have left an indelible mark on our hearts. Mochica has done that for thousands of people. He inspired generations."