Red crab migration
The red crab is by far the most obvious of the 14 species of land crabs on Christmas Island. Every year over 150 million red crabs move from inland shelters to the shore for their annual breeding season. This occurs at the beginning of the wet season (usually October/November).
The main migration can last up to 18 days. Masses of crabs gather into broad columns as they move toward the coast, climbing down high inland cliff faces, and over or around all obstacles in their way, following routes used year after year for both downward and return migrations.
Movement peaks in the early morning and late afternoons when it is cooler and there is more shade. Because if caught in open areas, in unshaded heat, the crabs soon lose body water and die.
Christmas Island is a small Australian-owned territory located in the Indian Ocean, approximately 300 miles south of Jakarta, Indonesia. A small population of 1600 residents live on the area of 50 square miles.
Sand bubbler crab
Sand bubbler crabs live in burrows in the sand, where they remain during high tide. When the tide is out, they emerge on to the surface of the sand, and scour the sand for food, forming it into inflated pellets, which cover the sand. The crabs work radially from the entrance to their burrow, which they re-enter as the tide rises and destroys the pellets.
