DETROIT (AP) — The Detroit Zoo has announced that an 8-year-old polar bear named, Suka, has successfully given birth to two cubs.

The unnamed twin cubs are the first polar bears to be successfully born and raised at the zoo in more the 15 years.

Suka gave birth to cubs in 2018 and 2019, but they didn’t survive. Though the announcement and details of the latest births came Thursday, the cubs were born in November.

The father is a 16-year-old polar bear named Nuka.

One of the two cubs, a female, is being raised by humans after early health issues.

Zoo officials say the rare separation of sibling cubs will help researchers study outcomes of cubs raised by humans versus those raised by their mothers.

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