Polar Bears Shift From Seals To Bird Eggs As Arctic Ice Melts

2017-05-17T17:01:05+00:00 May 17, 2017|
Polar bear diets are changing as ice melts. (Credit: Shailapic76/Flickr)

(Click to enlarge) Polar bear diets are changing as ice melts. (Credit: Shailapic76/Flickr)

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.

(From New Scientist / By Thom Hoffman) — 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.

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.”

In response, the bears are retreating from the coast. The tracking devices show them wandering greater distances in search of alternative land-based food. The bears also spend a lot more time near bird nesting grounds, which suggests eggs have become a significant food source.

But they would need an immense omelette to replace a seal breakfast and this type of mass egg hunting can devastate nesting bird populations.

Read the full story here: https://www.newscientist.com/article/2130821-polar-bears-shift-from-seals-to-bird-eggs-as-arctic-ice-melts/