Photo: Parks Australia via AP.
A road closed sign next to red crabs during their annual migration on Christmas Island, Australia, in October 2025.
I’m belatedly checking in on this year’s red crab migration. It happens annually on Australia’s Christmas Island, which, according to Wikipedia, “derives its name from its discovery on Christmas Day 1643 by Captain William Mynors.” I have reports from both Public Radio International’s The World and People magazine.
From AP’s Rod McGuirk via The World: “Tens of millions of red crabs are making their way to the ocean as part of their annual migration on Christmas Island, where a much smaller human population uses leaf blowers and garden rakes to help them on their way.
“Christmas Island National Park acting manager Alexia Jankowski [said] there were up to 200 million of the endemic crabs, also known as Gecarcoidea natalis, on the tiny Australian island territory in the Indian Ocean. Up to 100 million were expected to make their way from their forest burrows to the shoreline where they breed.
“The start of the Southern Hemisphere summer rains [triggered] the annual odyssey.
“The crabs seek shade in the middle of the day, Jankowski said, but early mornings and late afternoons bring about a vast, slow march that sees them move to the coast over roads and gardens. …
“ ‘Some people might think they’re a nuisance, but most of us think they’re a bit of a privilege to experience. 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. 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,’ she added.
“On the shores, the male crabs excavate burrows where the females spend two weeks laying and incubating eggs. The females are all expected to release their spawn into the ocean at high tide. … The young spend a month riding the ocean currents as tiny larvae before returning to Christmas Island as small crabs.
“ ‘When they’re little babies only about half the size of your fingernail, we can’t rake them, because you’d crush them. So, instead, we use leaf blowers,’ Jankowski said.”
At People, Rachel Raposas adds, “The mass migration heavily impacts regular human activity across Christmas Island.
“Footage captured by ABC shows a small road completely overrun by red crabs, slowly but surely all heading in the same direction towards the sea. During the migration, no space is off limits to the crabs, ABC reported, including busy streets and people’s homes. …
“Alexia Jankowski, Christmas Island National Park’s acting manager, told ABC [that] many residents try to avoid driving during the early morning and late afternoons to give the crabs ‘freedom’ during this important time.
“The migration is kicked off by the island’s first rainfall of the wet season, which is usually in October or November but can be as late as January, per the National Park’s site.
“The crabs’ migration is dictated by the moon and the tides, according to the park. The crabs consistently spawn eggs ‘before dawn on a receding high-tide during the last quarter of the moon,’ which the creatures somehow interpret each year.”
Isn’t amazing how critters know when and where to migrate or spawn? Read up on this at AP via The World, here, and at People, here. The pictures of crabs crawling over everything might creep out the uninitiated, but on Christmas Island, most folks love and protect their crustacean neighbors.
Suzanne's Mom's Blog 