Auckland Zoo's Sumatran tiger Zayana Photo: Supplied / Auckland Zoo
A Sumatran tiger cub recently injured at Auckland Zoo has had to be euthanised.
The cub is one of two siblings, born on 2 January, who were estimated to weigh a little under 1kg, the zoo said at the time.
The four-week-old cub sustained a head injury after a tumble while exploring his habitat on Saturday afternoon, the zoo said in a post on Facebook on Tuesday.
Auckland Zoo director Kevin Buley confirmed to Checkpoint the accident happened while his mother had left him on a ledge when she went to feed.
The tigers' habitat was temporarily closed to provide a quiet environment for the cub's recovery and to keep him suckling normally.
However, his condition appeared to deteriorate and they make the tough call to euthanise him on Tuesday morning, the zoo said.
"The initial hope was that it was a mild concussion but over the last three days it became apparent the injury was a lot more serious," Buley said.
"It's hugely upsetting for everyone connected with the Zoo, but nobody is more devastated today than our team of carnivore keepers who have been doing an incredible job supporting Zayana throughout her entire breeding journey," he said.
"Working with our keeping staff, our dedicated veterinary team have done absolutely everything that they could have done over the last 72 hours, to give the little cub the best possible chance of recovery after his accident, but it was not to be."
The zoo noted their mother, five-year-old Zayana, had been doing a fantastic job rearing both offspring and she was close by as they became increasingly active and explored their environment.
"Zayana moves the cubs around to various points within the habitat, we trust in her to do that and all the signs were that she's been a brilliant mum," Buley said.
"She'll drop them off in different areas and go off to feed and then come back and suckle them as a good mum would. In this particular instance, where she left them allowed the male - and these cubs are getting increasingly active as they grow and start to explore for themselves - he fell off one of the ledge areas where she'd left him, and that caused him to sustain a head injury."
The fall was from a couple of metres high, he said.
"Obviously these are young cats, it's very much a freak accident and not one that we could plan to avoid as it were.
"Devastating though it is, we remind ourselves that tigers in the wild, the mortality rate is incredibly high. Over the course of a lifetime for a female tiger, only two cubs will survive on average.
"Our goal is to always let Zayana be as naturally behaved as possible and trust her to make the right choices for those cubs.
"The area where he fell off, she currently doesn't have access to. So we're having a look at what exactly went on there and what potentially we could do to improve that area."
Last September, Zayana also gave birth to two cubs, but one of them died during delivery. Left with only one offspring, the tiger killed the cub in an instinctual attack.
The cubs' birth follows a breeding recommendation from Zoos and Aquariums Association of Australasia Sumatran tiger Species Management Plan for parents Zayana and male Ramah.
The regional programme is part of the World Association of Zoos & Aquariums global species management plan for this critically endangered big cat whose population numbers fewer than 400 in the wild.
Internally within zoos, there are close to another 400 animals, as part of zoos' global breeding and advocacy programme for the
The zoo said Zayana was initially searching for the male cub but on Tuesday was seen focusing on the remaining female cub, and the team was hopeful that this would remain the case going forward.
The tiger habitat remains closed to visitors while the team closely monitors Zayana and her remaining cub.