The migration is usually synchronized all over the island.
The males lead the first wave of the migration and are joined by females as they progress.
The crabs take about five to seven days to reach the sea.
The rains and moist overcast conditions make their journey to the sea long and difficult.
The bright red carapaces and sheer density of crabs make their routes to the sea observable from the air.
Human activities have led to increased numbers of red crabs being killed during their annual migration.
The crab migration and the crab bridges have become a great tourist attraction.
