One of two male western lowland gorillas at the Cleveland zoo has died, several years after he was diagnosed with heart disease, zoo officials said.
Bebac, 32, died on Friday, leaving fellow gorilla Mokolo, 29, as the zoo's only specimen.
"This is an extremely difficult loss for everyone connected with Cleveland Metroparks Zoo," it said on its Facebook page.
Officials asked people to support the zoo's gorilla conservation programme in remembrance of Bebac. The effort is aimed at protecting vulnerable gorilla populations in Rwanda and the Democratic Republic of Congo.
Both the zoo's gorillas were diagnosed with heart disease in 2008. The zoo sought to manage their symptoms by altering their diet and encouraging foraging behaviour.
A number of US zoos have western lowland gorillas in captivity. Harambe, a lowland gorilla, was shot dead at the Cincinnati zoo in May last year after a child fell into his enclosure, causing an outcry.
Gorillas can live for 50 years or more, both in the wild and in captivity, though such a long lifespan is rare.
Colo, a female at the zoo in Columbus, Ohio, is the oldest gorilla in the United States at age 60.
Related Story