Archive: Nuka the Polar Bear Returns to the Detroit Zoo

March 8, 2023

ROYAL OAK, Mich., 

The Detroit Zoological Society is saying “hello again” to a familiar face this week.

After nearly a year away, male polar bear Nuka has returned to the Detroit Zoo. Born at the Denver Zoo on Nov. 25, 2004, Nuka lived at the Detroit Zoo from 2011 to 2022. While at the Detroit Zoo, Nuka successfully mated with female Suka, resulting in the birth of twins Astra and Laerke on Nov. 17, 2020.

In March 2022, Nuka moved to the Toledo Zoo on an Association of Zoo and Aquariums Species Survival Plan (SSP) recommendation. There, he successfully sired two cubs with female polar bear Crystal. Nuka’s transfer back to the Detroit Zoo was recommended by the SSP, a cooperative population management program that helps ensure the sustainability of healthy captive animal populations. This program is vital to sustaining polar bear populations in zoos and has resulted in many successes, including the births of all Nuka’s cubs.

Now that he has completed his quarantine period, Detroit Zoo officials hope Nuka’s return will again result in a successful coupling with Suka.

On Feb. 8, 2021, female polar bear Anana died during a breeding attempt at the Detroit Zoo. Initially, it was thought that Nuka may have caused her death, but this was not the case. An in-depth review in March 2021 discovered Anana died from advanced heart disease. Analysis of Anana’s heart tissues showed that she experienced acute heart failure or a fatal arrhythmia before or during breeding attempts. It was impossible to know that she had a cardiac condition called multifocal myocardial fibrosis, as she showed no clinical signs, and a 2020 medical examination noted no abnormalities in her heart function. Wounds on Anana likely resulted from Nuka holding her with his teeth, as is typical during polar bear breeding. He was also observed moving her around the habitat after she became unresponsive, possibly because he was confused by her behavior.

Having followed all the proper procedures and investigated the matter fully, Zoo experts have no reason to believe Nuka is a danger to Suka or any other polar bear.

Currently, there are only about 55 polar bears in 25 AZA-accredited zoos and aquariums. Detroit Zoo officials are thrilled to welcome Nuka back so he can continue to be a part of ensuring the future of polar bears.