PORT DOUGLAS | Walk along Four Mile Beach in Port Douglas, Queensland, and you’ll notice millions of little sand balls and tiny holes spread across the shoreline below the high tide mark. You might wonder what’s going on, as I did when I encountered them for the first time.
They are the creation of ghost crabs that inhabit the beach. At twilight each day, as the tide retreats, thousands of ghost crabs emerge from the holes and begin to feed on microscopic material in between sand grains. Once they’ve stripped the sand of nutrients, the ghost crabs roll the sand into balls, and throw it behind them. Some arrange the balls in piles, others in rows that radiate out from their burrow.
Ghost crabs are named for their generally pale colours, translucent appearance, nocturnal lifestyle, and the way that they seem to appear out of nowhere, and disappear just as fast, as they move through their burrows. Ghost crabs aren’t harmful, and hide when they sense danger, making them hard to spot.
You may spot a ghost crab on the beach during the day, but blink and you’ll miss it. The scientific name for ghost crabs is ocypode cordimana, meaning swift foot. Accounting for scale, if a ghost crab was the size of a human, they’d move anywhere between 340 to 530 kilometres and hour.
Four Mile Beach