Christmas Island (an Australian external territory in the southern Indian Ocean) ~ At the beginning of the wet season (October-November) more than 150 million red crabs move from inland shelters to the shore for their annual breeding season.
libutron: “ Red Crab Migration Every year, in the Christmas Island, Australia, around 100 million of red crabs migrate in mass to the sea to spawn. This takes place each year around November, after the start of the wet season and in synchronisation.
The Astonishing Annual Red Crab Migration. Each year millions of bright red land crabs leave their burrow homes and head towards the sea to lay their eggs, eventually returning with their offspring in tow - Christmas Island, Australia
Crabs get their own bridge to cross busy road on Christmas Island
Crabs get their own bridge to cross busy road on Christmas Island - Telegraph
The annual Christmas Island Red Crab migration. Each year an estimated 43 million land crabs migrate to lay their eggs in the ocean. Authorities close most of the island’s roads during the migration, which normally takes at least a week.
Choose Your Magic Travel: Christmas Island, red crab migration
Christmas Island Crabs--"When the wet season blows into Christmas Island each year, millions of Christmas Island red crabs hike for several days, from a high rain forest plateau down to Indian Ocean beaches, where the crabs mate in burrows.