Up to 200 Million Red Crabs Migrate on Christmas Island

Tens of millions of Christmas Island red crabs have begun their annual migration to the sea after the onset of the Southern Hemisphere’s summer rains; park officials say the island hosts up to 200 million of the endemic Gecarcoidea natalis, with as many as 100 million expected to move to the shore. Residents and authorities are assisting the crabs using leaf blowers, rakes, specially built crab bridges, road closures and radio updates, and even adjust work and driving routines to avoid harming the procession. The migration is expected to peak in mid-November (around Nov. 14–16) with females releasing eggs at high tide, followed by a second spawning in mid-December, and larvae spend about a month at sea before returning as juveniles. Officials say the crab population has rebounded from roughly 55 million in the early 2000s to much higher numbers, a recovery partly attributed to the introduction of a microwasp that helped reduce invasive yellow crazy ants, a major predator. Locals describe the event as a privilege despite occasional disruption — crabs can spill into homes and line driveways, so communities actively “rake out” crabs to protect both animals and people.