Over 100 Million Red Crabs Begin Annual Migration on Christmas Island

Christmas Island hosts a spectacular annual migration of its endemic red crabs, with populations estimated to have recovered to potentially 180 million after pest control efforts, including the introduction of Malaysian micro-wasps to combat invasive yellow ants that prey on the crabs. The crabs spend most of their lives in the island's humid rainforests and emerge en masse to migrate to the coast for breeding, a journey timed with the first rains of the wet season and lunar cycles. This synchronized migration causes roads to be closed and locals to assist the crabs' passage, as the species is protected. While the exact causes of bumper years for returning baby crabs remain unclear due to factors like ocean currents and predation, climate change may influence future migration patterns by altering rainfall and dry season severity. Conservationists celebrate the migration as a natural spectacle, drawing tourists and inspiring efforts to preserve this keystone species despite ongoing challenges from pests. The red crab migration is regarded as one of nature's great events, underscored by its ecological importance and the island community's commitment to its protection.