Berlin zoo says its polar bear cub's parents were brother and sister

Genetic testing has revealed that a baby polar bear at Tierpark Berlin zoo is the product of breeding between siblings.

A clerical error meant that a female polar bear, Tonja, born at Moscow Zoo, was listed as the daughter of the wrong parents, a spokeswoman for Tierpark Berlin told CNN on Wednesday. Tonja was assigned documents meant for another female polar bear born at Moscow Zoo two days later, but in fact she was the offspring of the same parents as Wolodja, a male polar bear with whom she later mated in Berlin. The pair produced baby Hertha, who was born in December 2018.