Scientists have found that polar bears are using up to four times more energy in order to survive due to ice loss in the Arctic. The scientists say polar bears are using more energy for a reduced caloric intake than they previously had been. Polar bears feed mainly on the blubber of ringed and bearded seals, a food source that is becoming harder to come by. The areas of sea ice over shallow-water, which polar bears use for hunting seals, has shrunk 13% every decade since 1979. Polar bears are now having to swim for up to three days hunting for seals or rely on less energy-dense terrestrial food. A polar bear would have to eat 74 snow geese in order to equal the energy available from the blubber of one ringed seal. The scientists published their findings in the Journal of Experimental Biology.