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. This spectacular mass movement commenced after the first seasonal rains last weekend, sending the crabs on their crucial journey from their burrows to the coast to breed. As they traverse the landscape, the island’s roads literally turn red.
A poignant moment captures a young boy walking amidst the sea of red crabs during their annual migration, highlighting the close interaction between humans and nature on the island.
Living with a Crustacean Invasion
For Christmas Island’s 1,200 human residents, life seamlessly adapts to this incredible crustacean commute. The crabs move indiscriminately, crossing roads, gardens, and even making their way into homes if doors are left open. Alexia Jankowski, acting manager of the Christmas Island National Park, notes, “They’re indiscriminate. So whatever they need to get over to get to the shore they will go over it. 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 go out of their way to ensure the crabs’ safe passage. “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 further explained.
Despite the occasional inconvenience, residents largely view this annual event as a unique privilege. “Some people might think they’re a nuisance, but most of us think they’re a bit of a privilege to experience,” she shared.
A Delicate Breeding Cycle
This grand march is entirely driven by the need for reproduction. Upon reaching the shore, male crabs diligently dig burrows where females will incubate their eggs for approximately two weeks. The grand finale of this event is anticipated around November 14 or 15, coinciding with the last quarter of the moon, when the females collectively release their eggs into the ocean at high tide.
Following this, the crab larvae will embark on a month-long journey riding the ocean currents before eventually returning to the island as minuscule juveniles.
Leaf Blowers to the Rescue
The conservation efforts take a rather amusing turn when the baby crabs, each no bigger than half a fingernail, begin their journey back inland. Their tiny size renders traditional rakes ineffective 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 detailed.
Christmas Island is home to an astonishing total population of about 200 million of these endemic red crabs, scientifically known as Gecarcoidea natalis, making this yearly migration one of the most unparalleled wildlife spectacles on Earth.