RACINE, Wis. (CBS 58) -- The Racine Zoo is mourning the loss of one of their beloved animals. Yellow, an African penguin that was a favorite among zoo visitors, has died. She was 34 years old. 

According to the Racine Zoo, Yellow arrived at the zoo in 2007 and was known for her yellow band on her left flipper.

Yellow was born Feb. 17, 1991, and was the third largest African penguin currently in AZA zoos. 

The zoo says life expectancy for African penguins in the wild is 15-20 years, and under human care life expectancy can reach 20-30 years.

According to the zoo, Yellow began developing arthritis as she got older and received medication to ensure her comfort. In recent months, Yellow's health declined and on Feb. 4, she was humanely euthanized surrounded by her animal care team. 

"She will be missed dearly,"

-Racine Zoo

Yellow had a companion at the zoo, a male penguin named Bob. The zoo says even as other penguins in their colony changed mates over time, Yellow and Bob stayed loyal to each other. 

The animal care team will be keeping a close eye on Bob as he adjusts to Yellow's absence. 

Yellow, African penguin at Racine Zoo Racine Zoo