Polar bears were found eating dolphins for the first time. This act provides more evidence on how global warming is affecting the behavior of animals and how polar bears are changing their diet for survival.

Researchers at the Norwegian Polar Institute saw two polar bears eating the white-beaked dolphin while scouting Svalbard in the Norwegian Arctic in April 2014. This is the first time they observed the polar bears eating such species. They also saw that after eating the dolphin, one bear covered up the remaining parts with snow, probably saving it for a later meal. Since the first incident, the team saw seven more dolphin carcasses in the following months, according to LiveScience.

"This is the first record of this species as polar bear prey," wrote the researchers in a paper published June 1 in the Polar Research journal. "The warming of the Arctic is significantly changing the ecosystem and relations between species."

Polar bears usually rely on seals and other marine mammals for food. When the sea ice melts, they hunt for different foods like snow geese, mushrooms and berries. However, since the Arctic sea ice continues to melt due to global warming, the polar bears are unable to feast on their regular diet, so they started eating whatever is available.

Earlier this year, polar bears were seen migrating towards icier regions in the North where they can have more access to prey and mates as their original habitat continues to melt. These animals can't survive long in an area with less sea ice so they rather stop eating than swim in the waters, which is probably the reason why one of the bears photographed by researcher Joan Aars is skinny.

The researchers also noted an unusual behavior on the dolphins' side because their species usually visit the area during summer, yet they were found in early spring.

"White-beaked dolphins are frequent visitors to Svalbard waters in summer, but have not previously been reported this far north in early spring," they wrote. "We suggest they were trapped in the ice after strong northerly winds the days before, and possibly killed when forced to surface for air at a small opening in the ice."

While the flexibility of the polar bear's diet may have advantages, it is unlikely that their foraging can save them from the effects of global warming.