Tens of millions of red crabs on Christmas Island are on the move from the forest to the coastline in one of the world’s great wildlife migrations.
Christmas Island National Park staff spend months preparing for the migration each year erecting temporary barriers along roadsides to funnel crabs toward specially constructed crab bridges.
It begins with the first rainfall of the wet season with the speed of the migration determined by the phase of the moon. Red crabs always spawn before dawn on a receding high tide during the last quarter of the moon.
With the first rains arriving last week the crabs began their journey with huge numbers of crabs moving from the forest to the sea over the cliffs and through the township.
This year the spawning event is expected to take place on the 29-30 November 2021. It is then that each female red crab will release up to 100,000 eggs into the Indian Ocean.
Christmas Island is an Australian territory in the Indian Ocean, lying south of Java, Indonesia. A national park covers most of the 135-sq-km island, offering rainforest hikes to wetlands and waterfalls like Hugh’s Dale. Native wildlife includes nesting seabirds and the red crab, a land species known for its late-fall migration to the sea. The island is ringed with snorkelling and diving reefs.