The caribou migration is a veritable feast for grizzly bears — if the bears can catch them. "American Arctic" premieres Wednesday, April 13 at 8/7c on PBS. [VID: Grizzly bears chasing a herd of caribou. Transcript: Away from the water, the caribou start to relax. It's a mistake. Caribou may be faster than bears on the open plain, but they must also rest the calves. Grizzlies and polar bears are almost the same species and increasingly overlap and interbreed, but grizzlies are a more serious thre

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