The Detroit Zoo is mourning the death of one of its female polar bears, who died this week during a mating attempt with another bear. On Monday, the Michigan zoo announced that Anana, a

20-year-old female bear, died when 16-year-old male Nuka was "attempting to breed her," according to a press release. Anana came to the Detroit Zoo in January 2020 and was first

introduced to Nuka at the end of March. The two bears lived together without incident in 2020, Scott Carter, the Detroit Zoological Society's chief life sciences officer, said in the

release. "This was completely unexpected and the Detroit Zoo staff is devastated by the loss of Anana in this sudden and tragic event," Carter said. As part of the Association of

management and conservation program that helps ensure the sustainability of healthy captive animal populations." The program is critical to sustaining the endangered polar bear species

and recently led to the birth of twin cubs at the Detroit Zoo last November. There are around 55 polar bears in 25 AZA-accredited zoos and aquariums, the release stated. The Detroit Zoo also

houses an adult polar bear named Suka, who lives in a private maternity den with one of her cubs. The last time the Detroit Zoo experienced the killing of one animal by another was in 1988.

The incident also involved polar bears.