Over the weekend, Netflix released its new nature documentary series, Our Planet, and one scene in particular is upsetting viewers.
Created by the team behind BBC’s acclaimed Planet Earth series and narrated by David Attenborough, Our Planet offers a stunning look at some of Earth’s wildlife in its natural habitats. The project took four years to film and required over 600 crew members to capture footage in 50 countries, spanning the globe from the Arctic to the South American rainforests.
And even more so than Planet Earth was, the Netflix series is clearly framed through the lens of climate change, showing how warming global temperatures, rising sea levels, and the shrinking of ice is directly impacting many of our world’s species.
One of those species is the walrus. Normally, Arctic walruses rest or “haul-out” after foraging periods on sea ice near where they eat. But as the ice shrinks (scientists predict that by 2040, the Arctic won’t have any sea ice at all during the summer months), the animals are forced in large numbers to haul-out on small slivers of beach closer to their foraging areas.
These massive haul-outs, which involve thousands of walruses huddling in close quarters, are quite horrifying on their own. Deadly stampedes, as Attenborough explains in Our Planet, can happen at any moment.
But Netflix captured something even worse. Some walruses, looking to move away from the large crowds to find some space to rest, scale a steep cliff overlooking the beach. The Our Planet crew were confused when these gargantuan creatures started slowly climbing the escarpment.
After resting on the 80-meter (262-foot) cliff, the walruses sense their friends below have now moved. Hungry and desperate to return to the water with them, the walruses begin to move off the cliff. They don’t understand that the fall will severely injure or kill them.
Netflix filmed hundreds of walruses falling off the cliff to their deaths. “It’s really hard to watch and witness this. It’s just so heartbreaking,” one of the filmmakers says in the behind-the-scenes video above.
Some scientists who study walruses say climate change isn’t necessarily to blame for this upsetting behavior, as instances of the animals falling to their deaths have been documented back when there was still plenty of sea ice for them to rest on.
But others say that these haul-outs used to be more rare and less dangerous. Anatoly Kochnev, a Russian naturalist who worked with the Our Planet crew, told the Atlantic that when he began studying these haul-outs three decades ago, they only included males. Now they include females and calves as well. The sheer size of the haul-outs could be forcing walruses to seek refuge in riskier areas. The World Wildlife Fund says that deadly scenes like the one in Netflix’s series are becoming more common as walruses continue to lose more of their natural habitats.