Zoo Knoxville is mourning the loss of its African Lion Sylvan.
Sylvan, a 23-year-old matriarch of the zoo's lion pride, passed away after a struggle with declining health over recent weeks attributed to her advanced age.
Her health began to deteriorate Thursday and she didn't respond to treatment overnight.
The zoo said it made the decision to humanely euthanize her Friday morning.
Sylvan was born in 1995 at the Kapama Game Reserve in South Africa. She arrived at Zoo Knoxville in March 1997 with male lion, Aslan.
Sylvan gave birth to three litters of cubs over the course of her lifetime and her daughter Elsa still lives at the zoo's Valley of the Kings habitat.
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There are three other lions at Zoo Knoxville, male lion Jimmy and females Ann and Zarina.
"The average life expectancy of African lions is 10-14 years in the wild and up to 20 years in human care," according to a Zoo Knoxville release.
Native to sub-Saharan Africa, African lions are classified as a vulnerable species.
“Sylvan was a beloved ambassador for her species and we will all miss her,” said Zoo Knoxville Director of Animal Care, Conservation and Education Phil Colclough. “She was fierce, noble and special, everything a lion should be.”