Australia's Hidden Islands (2017)

S1E3 Christmas Island

Christmas Island, situated off Australia's northwest coast, is the remnant of an extinct volcano and boasts the highest population of land crabs globally. Among them, the Red Crab leads in migration numbers, with around ten million residing in the island's central rainforest. Annually, these crabs embark on a treacherous 5 km trek to the ocean for mating. Upon arrival, the females remain in the burrows crafted by the males, patiently incubating for three days, all timed with the Neap tide, when the tidal difference is minimal...