By ROD McGUIRK with AP
Published on
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 Thursday 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 last weekend triggered the annual odyssey.
The slow march of millions of crabs
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.
Their 1,200 human neighbours on the island generally do what they can to clear the red carpet of crustaceans off the roads.
“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,” she added.
“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.”
Leaf-blowing baby crabs
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 on 14 or 15 November, during the last quarter of the moon.
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.
“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.”