Last month an expedition cruise ship from Heritage Expeditions bumped into an extraordinary sight during their trip to Wrangel Island: a dead Bowhead Whale with at least 180 Polar Bears around it. They alarmed some scientists who even came to some 230 bears. Two-hundred-and-thirty Polar bears! At one place. This week it was picked up by several news outlets (amongst others in the Netherlands), and the discussion under the items was fun to read. “See, Polar Bears are not endangered.” or “How come so many Polar Bears are seen together, don’t they have a territory?” And of course many references to climate change (that according to some was fake news).
What has happened there and how unique is it?
First of all, unfortunately, I wasn’t at Wrangel, so I haven’t seen the spectacle first hand. However, I’ve seen at least four dead whales stranded on Spitsbergen, and all attracted a fair number of Polar Bears (though by far not as many as on Wrangel). Polar Bears have an extremely good sense of smell so something as big and smelly as a dead large whale will attract bears from a wide area. Polar Bears don’t have a territory. They live in a quickly changing habitat with wind and water currents changing the position of the ice (and with that their food) all the time. Because of this, it doesn’t make sense to spent a lot of effort in maintaining a territory for Polar Bears. So it is not uncommon to see several Polar Bears not that far from each other.
Having said that, 230 is a vast number. But if you look at the latest sea ice charts and look at the current and historical situation at Wrangel, you see the sea ice has disappeared entirely near the island. This means that the bears in that area get stuck on land where they have to wait until the ice returns in winter. During this wait, they most likely just rest and sleep, as there isn’t much to eat on the island. Until a dead whale washes ashore, then they all wake up and try to have a bite. This explains the large numbers of bears at this location.
However, it’s not sure they will all get a bite. Even though there is a lot of food available, it still might mean some bears get hungry. There will be a hierarchy, with the big males chasing off smaller ones or females when they want to eat. With this much food available, they usually don’t mind sharing, but not all 230 bears can feed at the same time of course. So far the largest number of bears I’ve seen on a dead whale was 19. Then they can rotate, and even the smaller ones can get a bite. When the number gets too big, this doesn’t work anymore.
So special? Yes, very! But not unusual and only partially caused by climate change. It will give most of the bears at least a bit extra fat to survive until the ice returns.