Norwegian scientists have witnessed polar bears eating dolphins for the first time ever, and say climate change has caused the species to swim up north outside of their normal migration period.
Dolphins are a common sight in the northern seas, but they usually only migrate there in warmer summer months. However, due to warming Arctic waters the species have been seen up north in both the local spring and fall.
According to scientists, the Arctic seas have seen a strong retreat of ice and two nearly ice-free winters in recent years, which could have attracted the dolphins further north outside of their regular migration period. While there, they probably became trapped by the sudden arrival of dense ice blown in by sporadic and strong northern winds, and are caught by polar bears when they come up for air.
This is the same way that polar bears catch seals, their main source of nutrition, by walking out to sea on a bed of ice and catching the seal as they come up for air.
According to the study published in the latest edition of Polar Research this month, scientists first observed the feasting phenomena in 2014 when lead researcher Jon Aars and a team of scientists came across one polar bear feasting on two white-beaked dolphins. They also photographed the visibly thin polar bear burying one of the carcasses in the snow and storing it for later – something they had also never seen before, and could be the result of lack of food, said the study.
Image shows a male polar bear covering the carcas of a dolphin with snow to keep from other predators in order to eat later | Photo: AFP
“We think that he tried to cover the dolphin in snow in the hope that other bears, foxes or birds would have less of a chance of finding it. Maybe to be able to eat it a day or two later, once he had digested the first one,” said Aars.
At least six different bears have been seen eating dolphin since then.
According to Aars, the polar bears' new find will not damage their diet. However scientists have warned that climate change is threatening polar bear habitat, as warming waters cause the ice to melt that the bears rely on for reaching their prey.