Caribou haven't just adapted to Arctic summers, they're also prepared for the Arctic cold. | National Geographic Animals

Caribou migration routes are under threat. Each year, caribou make migrations in their hundreds of thousands across the Arctic. But as the climate warms, their ancient pathways are changing - and so is the frozen ground itself. #OurFrozenPlanet tells stories that land the urgency of climate change whilst inspiring hope that change is possible for us and the health of our planet. Discover more ➡️ https://www.bbcearth.com/our-frozen-planet | BBC Earth