Watch: Millions of red crabs swarm Australian island in annual migration
The migration kicks off every year with the first rainfall of the wet season on Christmas Island, which typically occurs in October or November, according to Christmas Island National Park officials.
Millions of red crabs swarm Australian island in annual migration
The annual red crab migration on Christmas Island has begun, as millions of crabs have emerged simultaneously from their burrows in search of a mate.
CHRISTMAS ISLAND, Australia – The annual red crab migration on Christmas Island has begun, as millions of crabs have emerged simultaneously from their burrows in search of a mate.
One of the largest animal migrations on the planet, the red crab migration in the remote Australian territory features crimson streams of crustaceans pouring over forest floors and roads as the crabs make their way to the ocean.
Footage of this year’s migration shows the animals overtaking areas as they scurry to their destination en masse.
Red crabs scurrying across a road in Christmas Island. (Indian Ocean Experiences via Storyful / FOX Weather)
One individual on Christmas Island had to be careful about where he walked as he filmed the migration on Thursday.
"Just don’t step on the little guys, but they are everywhere," he can be heard saying in his video.
The reason behind the red crab migration
The migration kicks off every year with the first rainfall of the wet season on Christmas Island, which typically occurs in October or November, according to Christmas Island National Park officials.
October and November occur during spring in the Southern Hemisphere.
Officials noted that the male crabs are the first to start migrating, leading the way to the ocean and having females join them en route.
Stream of crabs on Christmas Island up close. (Indian Ocean Experiences via Storyful / FOX Weather)
Once at the beach, the male crabs, which are usually the first to arrive, dig burrows on the lower terraces of the island.
The females then join the males in or near the burrows, where the crabs mate.
As the males leave and return inland, officials said the females stay in the burrows where they can each produce up to 100,000 eggs.
The females then leave their burrows and, upon high tide, crawl to the sea to release their eggs into the water. Once this is done, the females make their way back to their inland homes.
How the migration impacts Christmas Island residents, tourists
Red crab during annual red crab migration on Christmas Island. (@enriques via Storyful / FOX Weather)
The number of red crabs can be so overwhelming that, for the safety of the crabs, Christmas Island officials may temporarily close sections of roads on the island.
They also built "crab bridges" for the animals, so they have a way to cross roads without being vulnerable to oncoming traffic.
Christmas Island is located more than 1,200 miles northwest of Australia, similar to the distance between Los Angeles and Dallas.