Visiting during the red crab migration requires a bit of extra planning. Photo: Wondrous World Images
Visiting during the red crab migration requires a bit of extra planning. Photo: Wondrous World Images
Friday 5 January 2024

One of the world’s most fascinating migrations is now underway on Christmas Island in Australia’s Indian Ocean Territories, capturing the attention of wildlife lovers across the world.

Each year, the first substantial rain of the wet season starts the march of tens of millions of red crabs from the forest to the coast to mate and spawn. The red crab migration is an amazing natural process determined by moon, tides, and weather.

Christmas Island is located 1500 km from the Australian mainland, where Christmas Island National Park staff have spent months preparing for the crabs’ big journey.

Working in collaboration with the community and local stakeholders, Parks Australia staff play a key role in protecting the crabs when they begin their famous journey.

These efforts include diverting traffic away from migrating crabs and erecting kilometres of temporary roadside barriers to channel millions of migrating crabs to the safety of underpasses and overpasses.

Christmas Island National Park has led key programs to protect the red crab population, including tackling yellow crazy ants through biological control of their main food source, and through island-wide baiting programs targeting ant supercolonies. The effective suppression of yellow crazy ant supercolonies has allowed huge red crab migrations to take place with little impact from the ants. Thanks to efforts like these, the red crab population has more than doubled in the past five years from 50 million to more than 100 million.

Quotes from Derek Ball, Park Manager, Christmas Island National Park:

“The wildlife on Christmas Island is extraordinary and like no other place in the world. The red crab is the island’s keystone species and the annual migration is a fascinating phenomenon that the entire community helps facilitate.

“To help the red crabs safely make their journey from the forest to the sea, national park staff install road barriers, crab bridges and undertake traffic management, with many members of the island community pitching in and helping out.

“Over many years we’ve also targeted the red crabs biggest threat, the invasive yellow crazy ant. By reducing their numbers, the red crab population numbers are higher than we’ve seen in decades which is an outstanding result not only for the red crabs, but for the entire island eco-system.”