Saint Louis Zoo Pairs Related Polar Bears for Breeding

The zoo plans to breed a 5-year-old female and 4-year-old male who share the same biological father.

Updated on Oct. 29, 2026 in Wildlife

Saint Louis Zoo Pairs Related Polar Bears for Breeding

Live Poll

Should zoos be allowed to breed biologically related animals to maintain captive population numbers?

The Saint Louis Zoo is moving forward with a breeding plan for two polar bears, Laerke and Kallu, despite the pair sharing a biological father. The decision aims to address limited breeding options within the small captive population of the species.

Why it matters

The pairing highlights the complex challenges zoos face in managing the genetics of threatened species. With few available mates and space constraints, experts must weigh the necessity of reproduction against concerns regarding close biological relationships.

There are approximately 300 polar bears living in captivity globally compared to a wild population of roughly 26,000. These animals remain listed as a threatened species under the U.S. Endangered Species Act.

The players

Saint Louis Zoo

This accredited zoological park in St. Louis manages animal conservation efforts and houses various species.

Polar Bear Population Alliance

This organization oversees the management and genetic breeding recommendations for captive polar bears across the United States.

Laerke

She is a 5-year-old female polar bear currently residing at the Saint Louis Zoo.

Kallu

He is an almost 4-year-old male polar bear involved in the breeding program at the Saint Louis Zoo.

Nuka

He is the biological father of both Laerke and Kallu.

The details

Laerke, a 5-year-old female, and Kallu, a nearly 4-year-old male, both share Nuka as their biological father. The Polar Bear Population Alliance provides guidance for such pairings to balance genetic diversity and the welfare of animals in limited captivity.

October 2026: The Saint Louis Zoo announced the arrival of Laerke.

Culture Shift

This breeding effort reflects the ongoing tension between species conservation under the U.S. Endangered Species Act and the challenges of managing small, isolated captive populations. It marks a departure from traditional breeding practices that prioritize wider genetic diversity.

Visitors to the Saint Louis Zoo may see these bears as they interact in their exhibit space. The zoo intends to continue its efforts to welcome future cubs to the population.

The takeaway

Zoos must navigate difficult genetic trade-offs to maintain species populations in captivity. Responsible animal management requires balancing limited genetic pools with long-term survival goals.