April 18, 2016
Ten-legged Monsters of the Dark
- as seen by -Gill Braulik @Wildlife Conservation Society Tanzania Program@gillbraulikhttp://www.wcstanzania.org/
The long walk through the dark forest to my tent by the beach suddenly seems much less attractive now I’ve laid eyes on the ten-legged monsters that lurk by the path in the night.
I’m looking (from a safe distance) at a coconut crab – the largest living land arthropod in the world. Reaching up to 9 lb. (4 kg) and 3 ft. 3 in. in length (1 m) from leg to leg, it is clear why Charles Darwin called them “monstrous” when he encountered them on the voyage of The Beagle.
Coconut crabs can live to an incredible 60 years old, and are both nocturnal and unable to swim, living almost all their lives on land. This particular one is purple-blue in color, has thick strong-looking legs, and massive claws which, in combination, allow it to climb coconut trees and to hack through the shells of the coconuts to eat the flesh inside.
Coconut crabs used to occur across the Indian Ocean and western Pacific, but they have been hunted to local extinction in many places such as Madagascar and Australia. Now, they mostly persist on tropical islands. Misali Island, where we are currently conducting dolphin surveys, is a small uninhabited island off the west coast of Pemba Island, Tanzania, in the Western Indian Ocean and is an increasingly rare refuge where coconut crabs continue their lives largely undisturbed by humans.