Polar bear inbreeding on the rise as they struggle to survive

Polar bears are inbreeding due to a loss in Arctic sea ice, according to a new study.

The magnificent mammals are sometimes forced to mate with their closer relatives as their habitats become smaller and they struggle to survive.

Researchers found major demographic changes among polar bears in recent years, with their genetic diversity around 10 per cent lower than in the two decades leading up to 2016.

It comes from a study of the Svalbard Archipelago and the impact on their habitats becoming more isolated as the ice continues to shrink.

The animals are not always able to travel between subpopulations in search of a mate.

Open water barriers are lasting for increasingly long seasons preventing some animals from migrating between subpopulations in search of a mate, which results in inbreeding.

The study said: “The magnitude and rate of loss of genetic diversity and gene flow that we observed is alarming considering that polar bears have historically shown relatively little genetic differentiation even on a global scale, but now are facing increasingly strong climatic selective pressure.”

It added: “The results of simulations suggested that further loss of sea ice will lead to the continued erosion of local genetic diversity in polar bears of the Svalbard Archipelago and to increased isolation between local areas, especially if there is a concurrent decrease in the number of bears.”