A young boy walks amongst red crabs during their annual migration (Image credits: AP)

The annual red crab migration has begun on Christmas Island, with as many as 100 million crabs emerging from the forest and moving toward the ocean.The mass movement started after the first seasonal rains arrived last weekend, sending the crabs on their journey from their burrows to the coast to breed. The island’s roads have turned red as the crabs make their way across the landscape.

Living with a Crustacean Invasion

For the island’s 1,200 human residents, life adapts to the crustacean commute. The crabs are indiscriminate in their path, traversing roads, gardens, and even homes.Alexia Jankowski, acting manager of the Christmas Island National Park, explained to the Ardrossan Herald how it does not affect life on the island. “They’re indiscriminate. So whatever they need to get over to get to the shore they will go over it,” she said. “So if you leave your front door open, you’re going to come home and have a whole bunch of red crabs in your living room.”Locals generally do their best to help the crabs safely cross roads. “Some people if they need to drive their car out of the driveway in the morning, they’ve got to rake themselves out or they’re not going to be able to leave the house without injuring crabs,” Ms. Jankowski added.Despite the temporary inconvenience, the event is seen as a privilege. “Some people might think they’re a nuisance, but most of us think they’re a bit of a privilege to experience,” she said.

A Delicate Breeding Cycle

The march is all for reproduction. On the shore, male crabs dig burrows where the females will spend about two weeks incubating their eggs. The climax of the event is expected around November 14 or 15, during the last quarter of the moon, when the females will simultaneously release their eggs into the ocean at high tide, reports Ardrossan herald.The crab larvae will then spend about a month riding ocean currents before returning to the island as tiny juveniles.

Leaf Blowers to the Rescue

The conservation effort takes a funny turn when the baby crabs, each barely half the size of a fingernail, make their way back inland. Their small size makes rakes useless and dangerous.“So about a month after the spawning occurs, we’re down on the coast looking pretty hilarious actually wearing these backpack leaf blowers and blowing all these tiny little crabs off the road to try to reduce the impact of cars,” Ms. Jankowski said.The island is home to a massive total population of about 200 million of these endemic red crabs, scientifically known as Gecarcoidea natalis, making this migration one of the most unique wildlife spectacles on the planet.