Auckland zoo's last remaining Sumatran Tiger has been put down after a long illness.

Berani. 11 years old, was part of an international breeding programme for the endangered species and was born with two siblings which were sent across the Tasman to Sydney.

Auckland Zoo's carnivores team leader Lauren Booth was with Berani from the day he was born.

"I just love the way that you could come in in teh mornings and sometimes you'd call him inside for his breakfast ... but he'd just be out, sitting up on a platform just looking over the zoo and taking in the sights and the sounds.

He just would have this look on his face, these slightly sleepy eyes and this big fluffy face, just looking so regal and content, so handsome ... just his whole persona just completely dignified and adorable.

"You also knew that he was incredibly goofy and just that almost contradiction in his personality .. the awe that he could inspire in someone even like myself who had the privilege of working with him pretty much every day.

She said the gastrointestinal disease he had was difficult to diagnose and even more difficult to treat, had recently worsened and the zoo had run out of options.

"We had to make the decision to euthanise him which was really devastating for us, as you can imagine."

Berani had been on his own since their mother died last year, but she said that would not have contributed to his illness.

"Tigers are solitary by nature, so they don't require the same social structure as many other species."

She said they were building a new tiger exhibit and as part of that had been looking at getting some more tigers to share the space with Berani.

"That's still on the cards, and that's still something we're planning for in the future."

The work Auckland zoo and others were doing to help preserve tigers was vitally important, she said.

"In regards to Sumatran tigers they're still considered critically endangered and their population trend is still decreasing. There are as few as 400 left in the wild, which means things are pretty dire out there for them.

"The anti-poaching units that Auckland Zoo supports through Wild Cats Conservation alliance - where those units operate tiger numbers are increasing but if there are no funds for those units then tiger numbers are going to be hit really really hard.

"It is estimated that if numbers keep decreasing in Sumatra in the way that they are they could be extinct in the wild within the next 10 years.

"You come to the zoo, you see a beautiful, beautiful tiger like Berani and you realise that there's Beranis out there in the wild that are having a really really hard time.

"By connecting visitors with these animals we can actually secure a future for tigers in the wild, and hopefullly none of us will ever have to live in a world without tigers."