Red crab migration season is nearly upon us and rangers on Christmas Island have been busy preparing for the exciting annual event. The crabs have a long journey to make from the rainforests to the sea, and face many hazards along the way – including cars.
The island has 31 underpasses built especially so the crabs can get safely across the roads. Each year the rangers open the underpasses and clear out leaves, dirt and debris to ensure the crabs can get a clear run underneath – and not climb up the sides. Rangers have also set up the temporary crab fences that keep the animals off the road and lead them to the underpasses.
The island’s residents play a huge part in the successful migration, by slowing down on roads where there are a lot of crabs, and stopping to help move them out of harm’s way. Many locals keep a rake in their car over the migration season so they can move crabs easily and safely!
The first action of the migration is the movement of crabs to the sea. Males farthest inland are the first to move, and are joined by more and more crabs (male and female) as they progress toward the shore. Whenever they choose to set off we will be ready with clear underpasses and intact fences to give them their best chance to miss that encounter with traffic.
The crabs’ possible spawning dates this year are 7-8 December or 6-7 January 2016.
Tanya, Parks Australia
Watch the video below to see the rangers prepare for the migration