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Animal profile

Christmas Island Red Crab

Gecarcoidea natalis

MalacostracaRainforest floor and burrows on a tropical island, with an annual migration to the coast

Field profile

The Christmas Island red crab is a land crab that spends most of the year alone in a burrow in rainforest leaf litter. Once a year, tens of millions migrate to the coast to breed. The migration is timed to the lunar cycle and depends on the arrival of the wet season.

Scope note

This is an editorial profile, not a diagnostic field-identification guide or a substitute for current conservation assessments. Follow the cited sources on each fact for the evidence trail.

Published field notes

2024-02-03

Christmas Island Red Crab

Millions of land crabs march on a lunar schedule

Christmas Island red crabs leave the forest at the start of the wet season and walk to the sea, but the release of eggs is fixed by the moon: females spawn before dawn on a turning high tide in the last quarter, so the water is briefly still.

Read with evidence →

Christmas Island Red Crab | Daily Animal Facts