Do Coconut crabs (Birguslatro) really eat coconuts that is the question? Yes they do! And yes you do find these enormous crabs on Ibo Island in the remote Quirimbas Archipelago. But it turns out that while these huge crabs, also known as robber crabs or palm thieves, can actually eat an entire coconut, this is not the main part of their diet. They also eat fruit, seeds, nuts and the pith of fallen trees as well as insects, tortoise hatchlings, small dead animals and even rats! They are also known to prey on other crabs and to eat the carcasses of their own kind. Coconut crabs are nocturnal creatures which emerge from their burrows at night to find food.
The coconut is very useful to Coconut crabs as not only is the soft flesh delicious but they also like to use the huge nut shell for protection against their enemies when they are young. When they reach adulthood, however, they develop a hard exterior or exoskeleton which means they no longer need the shells. This makes them part of the hermit crab family and the largest arthropod in the world found on land, weighing in at a hefty four kilograms and growing as long as one meter!
Where you get coconut palms you get Coconut crabs, and these are usually islands – in the Indian Ocean (like Ibo and RolasIslands off Mozambique) and the Pacific Ocean towards the Gambier Islands. Imagine watching a huge crab climbing a tall coconut palm to fetch a coconut, drop it then drop itself too about four to five meters, with an incredibly hard fall – which it survives?!
Unfortunately this charismatic species is no longer found on Madagascar or in Australia thanks to human impacts – people used to hunt these crabs and some still do. Today, however, they are also preyed upon by huge rats it has been found, which were introduced to some islands. There are conservation laws set aside by the International Union for Conservation of Nature (IUCN) to protect this remarkable species in some areas but the crab is still classified as “data deficient” as no one knows whether they are really threatened or vulnerable at this stage.
Did you know that Coconut crabs cannot swim? They will drown if they stay under water for too long. However, the females have to let their eggs go in the sea where the tiny larvae hatch and lie on the sea bed until they find and enter a gastropod shell – an empty shell of a mollusc or a snail – in which to hide. They wear this shell and hang out with other hermit crabs until the shell becomes too small for them. They change as they grow and start to develop their hard exterior – these moult continually over periods of 30 days at a time until the crab reaches its huge adult size.
They then stay on the land and use their very good sense of smell to find their food. They can live to be as old as 60 but only get to be as huge as they are when they reach the age of about 40. During this long life, Coconut crabs may be land creatures but they still do need some contact with the ocean water in order to keep their gills moist. What the crab does then, is it dips its legs into the waves and rubs them over its gills and it also drinks the water to conserve its innate salt balance.
Picture a Coconut crab with a coconut – they have found their own way to open these huge fruits with their claws, taking several days to get to the fruit inside. Ripping off the husk in strips at the point where the three soft “holes” are on the nut, the crab then bangs on these, forcing one open with one of its legs until the coconut gives way and is therefore open to being eaten. These fascinating creatures can lift things that weigh as much as 28kg!
Now, all you have to do to see a huge Coconut crab is to take a holiday on Ibo Island in the spectacular Quirimbas Archipelago where the days are long and sunny and the attractions are many. Ibo is a fantastical destination with the third largest mangrove forest in the world and tidal sand bar beaches – you will find a Coconut crab on your walks.
And if you take a boat to nearby Rolas Island, there is a known population of these fascinating crabs that you can observe quietly. This tiny islandis devoid of people, allowing the crabs full run of the sand and the coconut palms. Get on a kayak and paddle your way around the mangroves, seeing unusual birds, plants and creatures.
For your very first sighting of the Coconut crab, contact us here, now and we can tailor make your holiday to Mozambique to enjoy Ibo Island and its stunning historical and cultural atmosphere.