The Toronto Zoo has lost one of its most popular residents, a majestic white lioness who went by the name of Nokanda.

Zoo veterinary staff euthanized the popular animal after noticing her health was declining a few weeks ago and discovering she was suffering from cancer as well as liver and gall bladder problems. Nokanda was 15 years old and had been born at the Philadelphia Zoo.

She was brought to the Toronto Zoo in 1997 and was part of a new African Savannah feature in 1998.

Nokanda gave birth to three male cubs, one in 1999 and two in 2000. The younger cubs live with her male companion, Rowdy, at the Toronto Zoo and her first cub, Simba, lives at Parc Safari in Quebec.

Nokanda had at least four grand-cubs, who were part of Simba's family.

In a released statement, Zoo keepers described Nokanda as "a pretty nervous large cat," who took a while to warm up to people but will be remembered as co-operative, gentle and curious.

Nokanda was playful with Rowdy and enjoyed her toys, according to her Zoo keepers.

They said they will miss her and will remember her fondly as a big and beautiful cat.

The wild lion population is rapidly decreasing, with an estimated 30-50 per cent decline due to habitat loss and lion and human conflict, according to Zoo keepers.