Footage has been captured of a polar bear hunting and eating a reindeer, a sight that’s never been fully caught on camera before. Make no mistake, however, this is not polar bears broadening their horizons and dabbling with new foods – the change in diet is likely a symptom of climate change pushing the endangered species inland.

Researchers recently described the hunt in the journal Polar Biology. The sighting took place on August 21 close to the Polish Polar Station in Hornsund, part of the Svalbard archipelago in northern Norway. 

The female polar bear was spotted by scientists near the research station. After it "disregarded some rather noisy people", the bear was seen lifting its head and intensely sniffing the air before drifting over towards five to seven reindeer that were grazing closer to the coast. The polar bear slowly crept up on the herd before charging at a male reindeer who dashed into the nearby waters, attempting to evade the attack. However, the polar bear followed and eventually sunk its claws into the prey some 25 meters (~80 feet) offshore.

After a long struggle in the water, during which the reindeer was repeatedly submerged, the pair eventually arrived at the waterline, where the bear began to rip open the reindeer and eat the flesh. 

Over the course of two hours, the bear ate the majority of the flesh, in between chasing away jealous Arctic foxes and seabirds. After the feast, the polar bear took a 12-hour nap nearby then returned the carcass for some leftovers. 

Although there has been some evidence of polar bears predating on reindeer in Svalbard before, this is the first time the whole act has been fully documented and filmed.

“Pre-2000 sources state that polar bears do not attack Svalbard reindeer,” the study authors write in the paper. “This report is the first description and documentation of the complete course of a polar bear hunt for adult reindeer in Hornsund.”

The researchers suspect that the polar bears are increasingly opting for this prey due to reduced ice cover in the area. The Arctic is one of the hardest-hit corners of Earth when it comes to climate change. Warming air and sea temperatures have driven an increase in Arctic sea ice loss, and with less sea ice around, the polar bears are driven inland and cut off from their typical prey of seals.

Plus, Svalbard’s reindeer are easy pickings. The researchers appear to suggest that reindeer here simply are not prepared for a polar bear attack, writing “the level of alertness observed among Svalbard reindeer is very low. When selecting feeding and resting sites, they appear to underestimate the risk of a bear attack.”

It’s unclear how this shift towards land-based prey may affect the wider ecosystem. Fortunately, reindeer numbers are set to further increase as the tundra climate warms, meaning there’s little risk of polar bears depleting Svalbard’s reindeer population. However, the researchers note that land-based food sources cannot provide bears with sufficient energy. Seals are covered in fatty blubber, which polar bears have the unique ability to digest and typically provides them with the energy needed to survive the cold Arctic climate. Considering the International Union for Conservation of Nature (IUCN) already classifies the polar bear as a vulnerable species, this is a problem they could do without.