Rains Trigger Mating Frenzy

Red Crabs on Ethel Beach

Heavy and sustained island-wide rainfall over the last week of November has finally set the famous Christmas Island red crabs off on their annual breeding migration.

Due to the delay in the onset of the wet season, Megan Lawrence, who recently moved to Christmas Island with her husband and two children was "starting to wonder if the crabs would migrate at all this year."

However for Megan and family, the wait was more than worth it. "Last night we went up to the main road and the crabs were scuttling everywhere, and we were all wandering around with our torches and squealing with delight!" exclaims Megan.

Vinyl barricade stopping Red Crabs

Described by celebrated naturalist, Sir David Attenborough as one of the most spectacular migrations on the planet, the mass march of red land crabs to the coast to mate turns the tropical island into a real-life Discovery Channel documentary.

The ubiquitous crabs take the most direct route possible from their burrows in the rainforest terraces down to the coast, turning roads, the golf course (where there's a penalty stroke should your ball accidentally hit one!) and beaches into a crimson carpet as they scuttle along. 

Even the school bus stops short of the school to avoid the high numbers of crabs that migrate through the school grounds where specially-designed devices have been installed to stop the crabs marching through the classrooms.

"The island's hotels and restaurants are bracing themselves for the arrival of nature-loving tourists from all over the world who flock to witness the migration," says Linda Cash of the Christmas Island Tourism Association.

However, the biggest challenge for the crabs during their migration isn't to look their best to wow camera-toting visitors, rather the much more critical task of safely crossing the roads.

Crabs crossing under road grid

"In recent years the community has made a great effort to reduce to number of crabs killed on the roads," says Ms Cash, who adds "there's a real appreciation of the importance of the crabs to both our fragile island ecosystem and our nature-based tourism industry."

"The local radio station broadcasts the crab bulletins to advise on the crabs' latest movements and roads where the crab numbers are thickest have been closed," explains Ms Cash. Dedicated rangers from the Christmas Island National Park have even rolled-out kilometres of plastic chutes along the side of roads to funnel crabs through specially-designed grids which allow crabs to pass safely under the roads.

"You know it's crab migration time when your see cars driving around with plastic rakes strapped to the roof or hanging out the windows," explains Ms Cash, who adds, "rakes are the most efficient way of removing the crabs off the road without harming them."

But not all islanders have adopted the rake as their preferred crab clearing device. "Some people still use the environmentally-friendly palm frond and I've even seen some gently coax the crabs off the bitumen with diving fins!" explains Ms Cash.

Long-time local, Karenn Singer, who has witnessed the migration many times, is still mesmerised by the spectacle. "You can never take it for granted, no matter how many times you see it - it's simply awe inspiring," says Ms Singer.

Clearing road of Red Crabs

The females are expected to spawn en-masse and release billions of larvae into the sea on 6 January, and then march back to their forest burrows, "so anyone who visits the island in the next six weeks will be lucky enough to witness at least part of this remarkable migration," add Ms Cash.

Regular updates on the crab migration, provided by The Australian Government's Director of National Parks, are at: http://www.christmas.net.au/experiences/red-crab-migration.html%20

Virgin Australia fly four times a week from Perth and Christmas Island Air operates a Malaysian Airlines charter once a week from Kuala Lumpur.