Little is known about the world’s largest terrestrial invertebrate, the coconut crab, which grows to what Charles Darwin described as “a monstrous size.”
As their numbers dwindle, coconut crabs need to be better understood, says Mark Laidre, National Geographic Explorer and an assistant professor of biological sciences at Dartmouth College. With a research grant from the National Geographic Society, Laidre has been studying the crab’s behavior and natural history in the Chagos Archipelago in the Indian Ocean, the Earth’s largest coral atoll, which boasts an undisturbed population of coconut crabs.
During Laidre’s two-month field expedition, he studied how the crabs open their preferred source of food: coconuts. Using a custom-built tool to measure their grip, Laidre found coconut crabs can produce up to 1,500 newtons of force, far more than any other member of the animal kingdom.