Photo by P. Nowosa/P. Ulandowska-Monarcha
Polar bears in Svalbard are continuing to expand the diversity of their diet as climate change diminishes their traditional hunting prospects, according to a team of Polish researchers who captured what they say is the first video of a bear stalking and killing an adult reindeer.
Biologist Izabela Kulaszewicz witnessed a polar bear chase a male reindeer into the water during a field study in 2020. The predator chased its prey down, attacked with its claws and teeth, then drowned the deer.
“I was shocked,” Kulaszewicz told Science magazine. “I thought reindeer were good swimmers, and the bear would have a bigger problem catching the reindeer. But it was totally different.” After dragging the carcass ashore, the bear ate more than half of it in one sitting.
The bear dragged the carcass to shore and spent hours devouring it as members of the research team captured the hunt on video. The researchers, in a published study, attribute the hunt to a combination of Svalbard’s rebounding reindeer population and diminishing sea ice polar bears traditionally hunt seals on.
Researchers during the 1970s and 1980s suggested polar bears couldn’t hunt reindeer because the latter were too fast on land. But evidence of bear hunting reindeer began surfacing in the early 2000s, although the video is the first recorded evidence.
In recent years Svalbard polar bears have been observed either newly or increasingly eating alternatives to seals such as bird eggs, dolphins and even grass. The Polish researchers stated bears are likely to continue shifting toward more land-based food sources.
Although the loss of sea ice is seen as posing a serious existential long-term threat to bears, recent surveys suggest bears have adapted to changing conditions, with both the population and health of bears thriving.