A Sumatran tiger at Auckland Zoo has killed her own newborn cub, a natural, instinctual reaction to losing the first of her litter to a stillbirth.

Zayana, a first-time mother, gave birth last Friday afternoon, Auckland Zoo said. The births were much anticipated, with news of the critically endangered cat’s pregnancy, the second in the zoo’s history, announced in July.

Zookeepers gave Zayana an ultrasound, “the only way to 100 per cent confirm a tiger pregnancy”, the zoo’s Jane Healy said, which required the tiger to undergo thorough training to prepare.

“Because of the relationships we’ve all built with her, Zayana is really trusting of us,” carnivore deputy team leader Nick Parashchak said.

Zayana, a first-time mother, gave birth at Auckland Zoo last Friday afternoon, September 1 2023, but lost one cub to a stillbirth and killed the other. Photo / Supplied

“She enjoys and is very cooperative and focused during training where she has a choice about participating and is rewarded with treats like meat and pet milk - which she loves,” Parashchak said.

However, Parashchak remained cautiously excited about the pregnancy at the time, saying the challenges of carrying to term and birthing were still to be overcome.

Parashchak outlined clear concerns about litter sizes: “For example, when there’s just one cub born, there’s a higher chance of mismothering as opposed to being more invested in caring for multiple cubs.

“We won’t know how many cubs Zayana will have until she gives birth, but for now we’re doing everything we can to support her to have the best possible pregnancy,” he said at the time.

Last Friday, Zayana gave birth to two cubs.

“But unfortunately, one of the cubs was stillborn and the other did not survive,” Auckland Zoo said.

“Our carnivore [zookeepers] were encouraged to see Zayana’s natural instincts come to the fore when she was faced with the challenging situation.”

By that, the zoo meant Zayana had killed her other cub.

“In the wild, the mortality rate for juvenile big cats is high - [up to 70 per cent] - and research shows that producing only one offspring creates an even tougher higher-stakes situation,” carnivore team lead Lauren Booth said.

Sumatran tiger Zayana looks out over her domain at the zoo. Photo / Dean Purcell.

“In zoo-based populations, survival rates for a single cub versus multiple cubs are also less successful,” Booth said.

‘Having a larger litter size offers Sumatran tigers the best chance of successfully rearing young, so when only one cub is born – a vulnerable situation, it’s not unusual for a tiger mother to kill the remaining cub, which is what has happened here,” she said.

Zayana will have another chance to mate with her partner, Ramah, when she goes back into heat.

“All going well, we hope she will go on to produce a litter of healthy cubs,” the zoo said.

“Importantly, Zayana’s own health and wellbeing is good. After an exhausting couple of days, she has had plenty of rest and care from the carnivore team.”

Raphael Franks is an Auckland-based reporter who covers breaking news. He joined the Herald as a Te Rito cadet in 2022.