Christmas Island Red Crab

Creature Feature – Christmas Island Red Crab

This week’s featured creature is the Christmas Island red crab. 

Famous for their bright red color and for their spectacular annual migration to the sea, this species is a land crab that is endemic to Christmas Island and Cocos Islands in the Indian Ocean.

Christmas Island Red Crab


Scientific Name: Gecarcoidea natalis

Kingdom: Animalia

Phylum: Arthropoda

Order: Decapoda

Family: Gecarcinidae 

Genus: Gecarcoidea

© Chris Bray

Christmas Island Red Crab Fact File

? Size: These are large crabs with their carapace measuring up to 4.6 in wide

? Distribution: This species is endemic to Christmas Island and Cocos (Keeling) Islands in the Indian Ocean

? Diet: Opportunistic omnivorous scavengers, these crabs eat fallen leaves, fruits, flowers and seedlings, but will also feed on dead animals (including cannibalising other red crabs), and human rubbish. They dominate the forest floor so have almost zero competition

? Behaviour: Like most land crabs, red crabs use gills to breathe and must take great care to conserve body moisture. Although red crabs are diurnal, they usually avoid direct sunlight so as not to dry out, and, despite lower temperatures and higher humidity, they are almost completely inactive at night. For most of the year, red crabs can be found within Christmas Islands’ forests. Each year they migrate to the coast to breed; the beginning of the wet season (usually October/November) allows the crabs to increase their activity and stimulates their annual migration. The timing of their migration is also linked to the phases of the moon

? IUCN Status: Not yet evaluated. Despite the introduction of the invasive yellow crazy ant, populations appear stable