COLUMBUS (WCMH) – A week after polar bear Anana gave birth to twins, her sister Aurora had twins of her own.
The twins were born Monday at the Columbus Zoo.
This is Aurora’s third time producing twin cubs; the first litter did not survive and Nora was born in the second litter on Nov. 6, 2015. Nora was hand reared by the Zoo team after Aurora left her alone in the den when she was six days old.
Just a few hours before the birth, one of the cubs born last week to Anana passed away.
“At this time both Anana and Aurora are attentively caring for their tiny cubs but the sudden loss of one of Anana’s cubs is a sad reminder of how fragile their lives are both in our care and in their native Arctic environment,” said Carrie Pratt, Curator of North America and Polar Frontier. “We remain hopeful for the survival of these cubs as well as for the future of polar bears.”
The father of all the cubs is 28-year-old Nanuq who came to the Columbus Zoo in 2012. As long as Aurora and Anana continue to care for cubs in their dens, Nanuq is the only polar bear visible to guests.
Nanuq is the oldest male polar bear to reproduce in a North American zoo. Nine-year-old twins Aurora and Anana arrived at the Columbus Zoo in 2010 when the Polar Frontier region opened. All three bears came from other zoos on breeding loans as part of the Association of Zoos and Aquariums’ Species Survival Plan (SSP) for the threatened species.
Female polar bears generally have their first set of cubs between the ages of four and eight years. Due to delayed implantation, the gestation period can range from about 195 to 265 days. Pregnant polar bears den in the fall and give birth, generally to two cubs, in the winter. The cubs grow quickly on their mother’s fat-rich milk before emerging from the den in the spring.
Polar bears are native to the circumpolar north including the United States (Alaska), Canada, Russia, Norway and Denmark (Greenland). They are at the top of the Arctic food chain and primarily eat seals. Polar bear populations are declining due to the disappearance of sea ice, and experts estimate that only 20,000-25,000 polar bears are left in the wild. Some scientists believe if the warming trend continues two-thirds of the polar bear population could disappear by the year 2050.