The Horrifying Christmas Island Crab Invasion
If you don’t like the idea of being trapped on a small island with millions of huge, bright red crustaceans scuttling everywhere, you might want to look away now.
The Christmas Island red crab is a land crab which spends most of it’s time living in burrows deep in the island’s forests. They eat anything they can get their claws on, scavenging around on the forest floor where they completely dominate the ecosystem. With no natural predators nothing argues with the red crabs over a meal. And no one goes camping in the woods on Christmas Island for obvious reasons!
Around October or November each year a scuttling red army goes on the move. The crabs leave their forest burrows and head to the beaches in their annual mating migration. Over 40 million of them and it takes about a week to get there. Nothing gets in their way either, they’ll quite happily come up your drive, in through an open door and straight through your house if it’s in the way.
Once they get to the beach, the crabs mate and after incubating in freshly excavated burrows the females release the eggs into the ocean and follow the males back to the forests. The entire activity is timed so that the eggs are released on the turning tide during the moon’s last quarter. The eggs hatch immediately on contact with seawater and they will spend three to four weeks at sea, before making the same journey as their parents back into the forests as little tiny crabs about 5mm across.
How the baby crabs know how to get back remains a mystery, but they do seem to have some sort of inbuilt navigation system. They babies will remain in the forests for about three to four years until they reach maturity and then will start making the annual journey to the beach to breed just like their parents.
It looks like a lovely Indian Ocean paradise, ideal for a relaxing holiday, but if the thought of millions of Christmas Island crabs gives you nightmares, don’t visit there during the breeding season.