Polar bears eat mainly ring seals, a small arctic variety that weighs about 60kg. But a Polish research team recently made the first video of a polar bear hunting and killing an adult reindeer.
According to Science, in summer 2020, biologist Izabela Kulaszewicz witnessed a polar bear in Norway’s Svalbard archipelago chase a bull reindeer into the water. It swam the creature down, wounded it with its claws and teeth, then drowned it.
The bear then dragged the carcass back to shore and feasted on it for hours. The research team’s cook captured the chase on video.
Video: Mateusz Gruszka CC BY 4.0
According to the Polar Journal, they later observed the same bear feeding on the carcass of a different reindeer the following day. The team has since published a paper that chronicles the extraordinary event, along with a record of other polar bear/reindeer interactions on Svalbard. Most of these have been fairly recent.
Polar bears expanding what they eat?
The hunt is noteworthy not only for its rarity but also for what it insinuates — that polar bears may be modifying their hunting in response to climate change.
While Ursus maritimus primarily feeds on ring seals, they also eat the much larger bearded seal. They also opportunistically feed on carrion, eggs, chicks, and adult birds.
The bear with its prey. Some researchers believe that polar bears will increasingly turn to terrestrial food as sea ice continues to diminish. Photo: P. Klicz and P. Nowosad
In the 1970s and 1980s, researchers theorized that polar bears couldn’t hunt reindeer (called caribou in North America) because the reindeer were just too fast on land. But by the early 2000s, they began noting evidence of reindeer predation. This documented hunt is the first record of the bear’s changing behavior.
Stempniewicz and her colleagues credit this to a combination of Svalbard’s rebounding reindeer population and how sea ice, which polar bears need to sneak up on seals, is diminishing.
The researchers anticipate that polar bears — which are classed as a marine mammal because they spend most of their time on sea ice — will continue to shift more toward land-based food sources.
