Polar bear cubs were born Saturday, Dec. 20 at the Columbus Zoo and Aquarium but they did not survive.
According to a release from the Zoo, animal care staff observed the births while monitoring the mother’s activity from a camera mounted in the den. The first birth, recorded at 5 a.m., appeared to be stillborn. The second cub was born about two hours later and the mother, Aurora, appeared to begin caring for it.
The Zoo team could hear the cub vocalizing and observed Aurora, an inexperienced mother, holding the cub in a proper nursing position. Despite Aurora’s apparent care for the cub, the cub’s vocalizations stopped by the afternoon and the animal care team was unable to see it.
The Columbus Zoo animal team, in conjunction with recommendations from other polar bear breeding facilities, made the decision not to intervene. Polar bear cubs are difficult to hand rear and disrupting Aurora’s maternal care was not advised.
Polar bears have one of the lowest reproductive rates of any mammal. The survival rate for a polar bear cub during the first few weeks of life is only about 50 percent.
“While we would certainly wish for a better outcome the birth of these cubs is a major step in our polar bear breeding program,” said Curator Carrie Pratt. “We will likely never know why the cubs did not survive but we do know Aurora is able to reproduce and she has gained experience. She’s still a young bear and has many reproductive years ahead of her.”
Female polar bear twins Aurora and Anana arrived at the Columbus Zoo in 2010 when the Polar Frontier region opened. The twins are now seven years old and both have mated with the 27-year-old male polar bear, Nanuq, who arrived in 2012. All three polar bears came from other zoos on breeding loans as part of the Species Survival Plan for the threatened species.
It is unknown if Anana is pregnant, however her desire to den and elevated progesterone levels indicate it is a good possibility.