Polar bears shift from seals to bird eggs as Arctic ice melts

12 May 2017

By Thom Hoffman

Polar bears are ditching seafood in favour of scrambled eggs, as the heat rises in the Arctic melting the sea ice. A changing coastline has made it harder for the predators to catch the seals they favour and is pushing them towards poaching goose eggs.

This is according to a team led by Charmain Hamilton of the Norwegian Polar Institute that monitored the movements of local polar bears and seals before and after a sudden decline in sea ice in 2006, which altered coastal areas in the Norwegian archipelago of Svalbard.

The researchers attached tracking devices to 60 ringed seals and 67 polar bears overall, which allowed them to compare their movements before and after the ice collapse.

Before the melt, when they were hunting on stable sea ice, the polar bears had a big advantage over their favoured prey. “Both sexes of all age classes successfully hunt seals by stalking or ‘still hunting’,” says Hamilton.

However, on a melting coastline punctuated by broken-up icebergs, the odds become stacked in the seal’s favour.

In deep water

The polar bears must now swim undetected towards the seals before launching themselves out of the water to grab their prey on the floating chunks of ice. Not all bears have mastered this explosive technique and there is a high failure rate even among those that have.

“It seems that currently, it is mainly large, male bears using this aquatic hunting method on Svalbard,” says Hamilton. “It is likely [to be] more energetically demanding than the traditional hunting methods.”

Continued