Photos are currently circulating in media that show how a polar bear is eating the carcass of a White-beaked dolphin. Both articles and comments that come with these photos are reason for some extended comments on the event.
The first observation was made in April 2014 by Jon Aars, polar bear researcher in the Norwegian Polar Institute, and his scientists, in Raudfjord, where they found a polar bear that was eating a dead White-beaked dolphin. They had not observed how exactly the dolphin had died. In the following time up to the summer, several other bears were seen eating more dolphins, but all further observations relate to the same event in the same area.
White-beaked dolphins are common in the Barents Sea including Spitsbergen waters, but tend to stay at open sea, away from coastal waters, and are accordingly not often seen. This contributes to the widely believed impression that there are no dolphins in the Arctic. This is not true. The statement that their “sudden” presence there has to be linked to climate change is obviously wrong, they have been there already for a long time, without any link to the present climate change. There are, however, observations of White-beaked dolphins in fjords.
It is safe to assume that a group of White-beaked dolphins was trapped by drift ice in Raudfjord that was blown in there by northerly winds during the days before the first observation was made. Inside the fjord, the dolphins were forced to surface regularly at small holes in the ice to breath. There, they are easy prey for polar bears, who often hunt seals in a very similar way. Polar bears can kill seals instantly by hitting them with the paw or biting them into the head. There is now reason why they should not be able to do the same with dolphins, which are of similar size, once they are forced to surface in ice similarly to seals.
Polar bears are very well known as opportunistic feeders, which means they will eat almost anything they come across as long as they can get it down. It is no surprise that they take dolphins when they can get hold of them. It would actually be very strange if they didn’t.
It is certainly true that polar bears do usually not eat dolphins. This is due to the simple fact that dolphins normally stay in open water, where polar bears are not able to catch them.
If it is now stated that polar bears, who can’t hunt their usual prey (seals) now because of climate change, are forced to change to dolphins, which – again due to climate change – have moved further north, there are obviously several very difficult, if not plainly wrong, assumptions involved. The observation rather means that man has not yet seen everything that occasionally happens in nature, especially in very remote areas in difficult seasons and with animals which are very difficult to follow. Especially when it comes to quite rare events.
Polar bear scientist Jon Aars is quoted saying that White-beaked dolphins may become an important food source for a smaller number of specialized polar bears. This lacks an explanation how these specialized hunters should get hold of those dolphins on a more or less regular basis, at least more than during a once in a lifetime occasion due to rare circumstances. Considering this and the fact that this is, so far, based on only one observed event, it seems a somewhat far-reaching hypothesis. (There is a number of photos taken on several opportunities, but all of them show the same group of polar bears feeding on the same group of dead dolphins in the same area).
Conclusion: this is certainly a rare event and an even more rare observation, which is, however, by no means necessarily linked to climate change, but due to an unusual constellation of circumstances.