Tierpark Animal News

What’s that sound?

Strange new noises from the polar bear birthing den at Tierpark Berlin.

The polar bear cub at Tierpark Berlin is now two weeks old, and daily life for the tiny bear and mum Tonja (9) still revolves around sleeping, suckling and cuddling. But while things may be quiet in the birthing den, they are by no means silent. You can always tell when the cub is awake because of the rather peculiar noises it makes. One such noise is an irritated growl when the baby can’t find one of its mother’s four teats quickly enough, another is a strange, rhythmic noise the cub makes when suckling that sounds rather like sawing. “Young polar bears produce these particular noises when drinking their mother’s milk,” says curator Dr Florian Sicks. “And that actually makes it easier for us to monitor the cub’s suckling behaviour.” The cub is currently drinking from its mother every three hours or so.

Tierpark Berlin’s female polar bear Tonja gave birth to her cub on 1 December 2018, at 2:33 a.m. She had mated with male bear Wolodja (7) several times in March and April. In the summer, Wolodja moved to Zoo Berlin to give Tonja plenty of peace and quiet for her presumed pregnancy and birth. In the wild too, polar bears are solitary animals, and males are not involved in raising the young.

Thanks to sophisticated new camera technology, the experts at Tierpark Berlin are able to watch the birthing den around the clock, and can even zoom in to see how well the cub is drinking. Infant mortality in polar bears is extremely high. In the wild, around 85 percent of polar bears do not live past their second birthday. Because absolute peace and quiet is crucial for the successful rearing of young polar bears, no one will approach the birthing den over the next few weeks.

The polar bears are currently not on view to Tierpark visitors. In zoos just as in the wild, mothers and their cubs do not leave their dens until the spring.