02/01/2012 05:44 pm ET

Adelor, Lincoln Park Zoo Lion, Dies: 18-Year-Old Lion Euthanized Amid Health Problems

Lincoln Park Zoo's alpha African lion, Adelor, was euthanized Wednesday when the zoo determined his health and quality of life were progressively deteriorating.

"Guests of all ages would flock to the lion exhibit when Adelor began roaring as he announced his territory several times a day," zoological manager Mark Kamhout said in a release. "He was a wonderful leader of the pride and was very protective and affectionate of the females under his care."

The 18-year-old lion had been at the zoo since 1995, and fathered five cubs, according to a release from the zoo. He is survived by female lioness Myra, 15, the sole remaining African lion at the zoo. Lincoln Park Zoo is working with the Association of Zoos and Aquariums to find new companionship for Myra, whose species is classified as vulnerable due to habitat loss throughout Africa.

Chicagoans and fans took to the zoo's Adelor memorial page to share their memories of one of Lincoln Park's most notable residents.

"RIP beautiful old guy and may your memories live on for many of us," wrote Amy Bucher, a former docent. "To the staff at the Zoo and to Myra--my deepest sympathies on this loss."