We are sad to announce the loss of Ramar, a 50-year-old western lowland gorilla today. Based on his quality of life, staff made the very difficult conclusion that euthanasia was the most humane decision for Ramar...read full story at https://t.co/tDw0WOI7KR. pic.twitter.com/eXE7jKLmZy— Brookfield Zoo (@brookfield_zoo) April 12, 2018
The 50-year-old western lowland gorilla outlived his life expectancy by nearly 18 years.
Ramar turned 50 in January but his health had been declining for some time.
A statement from the Chicago Zoological Society said "The CZS is sad to announce the loss of Ramar, a 50-year-old western lowland gorilla today, April 12. Based on his quality of life, staff made the very difficult conclusion that euthanasia was the most humane decision for Ramar."
Ramar was brought to the U.S. in 1969 after he was orphaned in the wild and raised by a human family until he was about 6 years old. He spent time in zoos in Philadelphia, Miami and North Carolina before arriving at Brookfield Zoo in 1998.
Zoo officials say Ramar was the sixth-oldest western lowland gorilla in a North American accredited zoo population. The median life expectancy for the animals is 32.
Ramar, who was the oldest animal at Brookfield Zoo, sired three offspring.
The Associated Press contributed to this article.