Millions of red crabs decorate Christmas Island for annual migration

Christmas Island has been decorated in time for the holidays after millions of red crabs started their annual migration.

Each year, the crabs leave their homes in the forest and march towards the ocean to mate and spawn in a sight that BBC presenter David Attenborough has labelled one of his "greatest moments on television".

The timing is determined by the moon - typically during the last quarter of the lunar phase - but a late wet season has led to a sporadic migration this year.

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Christmas Island Tourism confirmed the masses of crabs have begun their mission.

"Christmas Island's red crab army are again on the move… a few bouts of rain has started the annual march from the jungle to the sea," the tourism body said.

"We look forward to immersing you in the moments as one of the planet's biggest migrations takes place on Christmas Island."

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Road closures are in place across the island and motorists are advised to drive with caution so they don't harm the small creatures.

Christmas Island is 1500 km west of the Australian mainland and 2600 km from Perth.

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The red crab migration typically sees millions of eggs hatched in the ocean following the migration.

Sadly, a vast majority of the eggs will fail to survive as fish and whale sharks make their way to Christmas Island for their annual feast.

However, once or twice a decade, a large number of eggs will withstand the trials of nature and survive which maintains the island's mounting red crab population.