New research suggests polar bears being forced onto land by sea ice loss are eating terrestrial foods, and this strategy may not be sustainable.

"The bears are being forced off the ice earlier and they are not just going to sit around and wait for the sea ice to refreeze if there is something available for them to eat. The issue is whether or not eating these things will benefit the bears," said Steve Amstrup, chief scientist of Polar Bears International and a co-author of the study in Frontiers in Ecology and the Environment.

Like Us on Facebook

"The one terrestrial food rich enough to support bears is bird eggs. But the problem is that there aren't enough of those in the polar bear's range to make much of a difference,"

The United States Geological Survey reported some polar bears are believed to have expanded their palettes to include berries, birds, grains, and eggs. These foods aren't likely to be able to compensate for the absence of lipid-rich seals, which are polar bears' typical prey.

Many of these terrestrial regions are already inhabited by grizzly bears, but only at low densities because of food scarcity.

Polar bears are not "physiologically suited" to ingest plants, especially in large enough quantities to sustain their large body sizes. Foods found in the terrestrial environment tend to be rich in protein but low in fat.

Research also shows that one of the challenges is that the polar bears on land have to compete with grizzly bears for what food sources are available. These grizzly bears are among the smallest of their species because of their diet.

Researchers say the small population of grizzly bears in the Arctic provides a clear indication of the nutritional limitations of onshore habitats for supporting large bodied polar bears in meaningful numbers. Both grizzly bears and polar bears are likely to compete for terrestrial resources.

This is just the latest dose of bad news for the polar bears, which were added to the Endangered Species List due to the impact global warming is having on their icy world.

The findings were published in the journal Frontiers in Ecology and the Environment.

TagsScientists Reveal that Land Food is Not Good for Polar Bears, Polar bears, grizzly bears, bear, Land food not good for polar bears, Arctic region, terrestrial foods