Adult coconut crabs have no known predators apart from other coconut crabs and humans. Its large size and the quality of its meat means that the coconut crab is extensively hunted and is very rare on islands with a human population.[55] The coconut crab is eaten as a delicacy – and regarded as an aphrodisiac – on various islands, and intensive hunting has threatened the species' survival in some areas.[19]
While the coconut crab itself is not innately poisonous, it may become so depending on its diet, and cases of coconut crab poisoning have occurred.[55][56] For instance, consumption of the sea mango, Cerbera manghas, by the coconut crab may make the coconut crab toxic due to the presence of cardiac cardenolides.[57]
The pincers of the coconut crab are powerful enough to cause noticeable pain to a human; furthermore, the coconut crab often keeps its hold for extended periods of time. Thomas Hale Streets reports a trick used by Micronesians of the Line Islands to get a coconut crab to loosen its grip: "It may be interesting to know that in such a dilemma a gentle titillation of the under soft parts of the body with any light material will cause the crab to loosen its hold."[43]
In the Cook Islands, the coconut crab is known as unga or kaveu, and in the Mariana Islands it is called ayuyu, and is sometimes associated with taotaomo'na because of the traditional belief that ancestral spirits can return in the form of animals such as the coconut crab.[58]
Conservation