ADELAIDE Zoo is in mourning today after the death of its 83-year-old Greater Flamingo.

Affectionately known as 'Greater', the bird was a favourite among zoo goers for generations. It was put to sleep this morning after its quality of life had deteriorated due to complications associated with old age.

Arriving at Adelaide Zoo in the 1930s, Greater was best known for being the world's oldest flamingo and the last Greater Flamingo to have resided in Australia.

Zoos SA Chief Executive Elaine Bensted said last year it became apparent Greater was struggling to cope with the effects of arthritis. And despite responding well to the treatment, it took a turn this week.

"When Greater's physical health started to deteriorate last year, our veterinary team began a course of anti-inflammatory pain medication to ensure Greater's comfort," she said.

GALLERY: Adelaide Zoo's iconic flamingo

"Greater responded well to treatment and remarkably survived the cold winter. This week Greater took a turn for the worse and the difficult decision was made to humanely put Greater to sleep after Greater was no longer responding to treatment and Greater's quality of life had significantly deteriorated.

Ms Bensted said that despite the zoo's best efforts it was time to let Greater go.

"Although this is an extremely sad loss for us all, it was the right thing to do," she said.

"There was no additional medical treatment that would have improved Greater's quality of life. "We always knew our time with this beautiful Adelaide icon was nearing its end.

"Greater will be sorely missed by our zoo family, and no doubt the wider South Australian community."

Greater remained strong to the end, even surviving a vicious attack by three teenagers in 2008 which shocked animal lovers around the world.

Discussions are currently underway to explore options to erect a memorial to Greater near the heritage listed flamingo pond.