Saturday, April 24, 2021

Update: Anana's death was from natural causes

Anana in Brookfield Zoo, Chicago

The news of the tragic death of Anana at the Detroit Zoo on February 8, just a little over two months ago was all the more heartbreaking to think that another much loved bear, Nuka, had killed her during attempted breeding. Anana was adored by zoo visitors from the Brookfield Zoo, Buffalo Zoo, Cincinnati Zoo, and her final home at the Detroit Zoo.

It is a relief to know the truth now, with news of the results of the autopsy.

An independent commission of experts has studied what led to Anana's death, and their results were shared this week with Detroit Zoo members through an email. 

Anana in Cincinnati

The following was sent out in an email to the Detroit Zoo members this week from the Detroit Zoological Society.

DZS recently completed an in-depth review into Anana’s death and, working with veterinary pathologists at Michigan State University, discovered that she died from advanced heart disease. She was not killed by male polar bear Nuka, as was originally believed. The DZS’s Animal Health External Review Panel, a group of experts in veterinary and human health, endorsed this conclusion.
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.
While DZS continues to mourn Anana’s loss, the polar bear staff is focused on caring for Nuka, as well as female Suka and her 6-month-old cubs. Laerke (the cub being reared by staff) is living in the polar bears’ building, but is separated from the other bears while she gets to know them from a distance. Suka and Astra (the cub she is raising in the maternity den) will soon be exploring the Arctic Ring of Life’s Tundra habitat.


From the start, Nuka was presumed guilty, but now has been found innocent of causing Anana's death. It sounds like the wounds were inflicted upon her face and neck by Nuka's efforts to wake Anana up after her heart failure.

Nuka is the father of the Suka's twins and we will be able to see these cubs, one raised by their mother Suka and the other by keepers, in the coming weeks at the Detroit Zoo.  A shadow over the happy events surrounding the new cubs has been lifted with the news that Anana's death was from natural causes. 

Anana was born at Hogle Zoo in Salt Lake City on December 12, 2000. The petite lady bear, weighing in at only 450 pounds, had one daughter, 8 year old Luna, now living in the Buffalo Zoo with Suka's brother Sakari. Anana died of heart failure in Detroit on February 8, 2021.

Nuka, father of the cubs

Suka, mother of twins, in Detroit