Lanky, who will be remembered for his giant beak and occasional hissing, had been battling arthritis in his ankles for the past few years.

On Monday, Wellington Zoo announced that Lanky, the longest living resident at the zoo, had been put down.

"Lanky had regular medical examinations and we were able to manage the arthritis in his ankles with pain relief and anti-inflammatories, but his lameness increased over recent months," general manager of animal care Mauritz Basson said.

Lanky was finding it hard to bear weight on his legs, and stopped eating and taking his medication, he said.

"The welfare of our animals is paramount, and the observations showed we were no longer able to sustain his quality of life, so the decision to euthanise Lanky was made in his best interests."

Lanky was an Australian pelican, a bird with the longest beak of any bird in the world.

He arrived at Wellington Zoo in 1978, and has lived in a pond past the monkey islands for almost 40 years.

Stuff.co.nz