When Dutch naturalists made a stop at the Cocos islands on their way to Indonesia in 1820, they were struck by the cleanliness of the beaches. Usually, the beach is a great place to find remains of all sorts of washed up marine life – mussels, seaweed, fishes, etc. – but on the Cocos islands they could barely find anything. A little patient observation provided the explanation for this odd state of affairs: these islands are very rich in crabs, and crabs like to keep their front yard tidy. None more so than the adorable ghost crabs.
Ghost crabs can be found on beaches across the tropics and subtropics, where they make burrows in the sand in which they can hide from predatory birds, the water, the sun, and other crabs who want to steal their food. They eat basically anything the sea dumps on the shore, including jellyfish and fish corpses, which a group of ghost crabs can tear apart in mere minutes, dragging as many pieces to their burrows as they can. They can also be seen nibbling on sand, from which they eat the attached film of microorganisms. Their claws are quite powerful, making short shrift even of tightly-shut clams.
The image of these little crabs scurrying across the beach looking for food was used to great effect in the animated movie The Red Turtle, where the supporting cast is a small group of ghost crabs:
If you haven’t seen this movie yet, please do. It’s one of the most beautiful animated movies ever made. It got nominated for an Oscar, which it would have won if the Academy could finally get over Disney. But hey, what can you do.