Winston, one of the oldest gorillas in the world and a popular fixture at the San Diego Zoo Safari Park, has died after experiencing multiple health problems, officials announced. He was 52.

The western lowland silverback was euthanized on Saturday after experiencing several age-related conditions, including heart, kidney, and joint diseases, Safari Park officials said on Instagram. Visitors of the Southern California park adored him for his quirky but gentle temperament, and scientists treasured him for his contributions to a critically endangered species, including fathering nine offspring, according to zoo officials.

Winston also raised two unrelated male gorillas, an unknown behavior for silverbacks. 

"This gentle giant will be remembered for his quiet strength, easygoing nature, and heart of gold,” Safari Park officials said. "Winston served as the protector of his family."

Western lowland gorillas are a critically endangered species in several Central African countries, according to the World Wildlife Fund, a leading conservation non-governmental organization. How many live in the wild is unknown, but scientists estimate their numbers have fallen by 60% in the past 25 years.  

Winston arrived in Southern California in 1984, according to a San Diego Zoo Wildlife Alliance publication "Wonderful Winston: A truly great ape." He was one of 3,000 animals representing 300 species living at the 1,800-acre expanse 30 miles outside San Diego and oversaw a troop of 7 gorillas according to the 2018 publication. The park opened in 1972.

The beloved gorilla has had health complications since at least 2017 when zookeepers noticed symptoms of heart problems. Most great apes in zoos die from cardiovascular disease.

"After careful consideration stemming from furthering complications from his worsening conditions, and with Winston's quality of life top of mind, wildlife health and care teams made the difficult decision to compassionately euthanize him," zoo spokesperson Emily Senninger said in a statement.

What is the rarest animal in the world?See the list of top 10 most endangered species.

Western lowland gorillas

According to the Smithsonian National Zoo and Conservation Biology Institute, western lowland gorillas are the smallest subspecies in size and are known for being peaceful. The males can get up to 6 feet tall and 500 pounds; the females can grow up to 4 ½ feet tall and 200 pounds, according to the Smithsonian. Gorillas arms are longer than their legs and the males have an arm span of 8 feet.

Western lowland gorillas — given the scientific name gorilla gorilla gorilla — live in swampy forests across the Congo Basin, including in Cameroon, the Central African Republic, Equatorial Guinea, and Gabon, according to the Wildlife Fund. 

The number of wild western lowland gorillas worldwide has fallen sharply due to poaching and ebola. The deadly virus has killed off 90% of the gorillas and chimpanzees in what were some of the most densely-populated ape habitats, according to the fund. 

Western lowland gorillas in the wild typically live between 30 and 40 years, according to the Smithsonian. They can live into their 50s in captivity. 

'Cool as all get out'

The first thing zookeepers noticed about Winston when he arrived in the U.S. from England, where he was raised, was his mean-looking mug, according to a zookeeper publication. The second thing was how gentle he was.

He loved prunes, refused to eat honeydew melon, and had a cat-like aversion to getting wet, including walking around puddles or laying down a piece of cardboard to sit on when the ground was wet, according to zookeepers.

The announcement of his death was met by an outpouring of support from fans on Instagram, who shared stories of seeing him.

Elizabeth Washburn, a San Diego-based artist, told USA TODAY about the time she met him. 

Washburn was teaching at an art camp at the Safari Park in the early 2000s when a zookeeper invited her and the kids behind a special gate to watch Winston get a vet check.

"He was cool as all get out," Washburn, 51, said, recalling how the full force of his personality was on display in the enclosure. "He came in and made this giant entrance. He ran in and started pounding his chest, and then he immediately came up to the window, and looked straight out at us."

The kids, staring back at him across the fence about 10 feet away, were silent, "just gobsmacked," Washburn said.

"He had so much intelligence," the artist said. "You could just see it in his eyes, he was just looking at us, trying to see who we were."