Caribou, better known as reindeer in northern Europe, can live in herds up to 200,000 strong. The beautiful beasts undertake one of the longest land migrations of any mammal, travelling round-trip distances exceeding 745 miles. Sadly the number of reindeer and caribou has declined by 56% over the last two decades, with roughly 2.1 million individuals left in the wild. The team filmed them in Alaska’s Arctic National Wildlife Refuge during 24-hour daylight conditions.

You can see these wild animals in America's national parks

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