Coconut Crab

Birgus latro is the largest terrestrial invertebrate in the world, a giant land-dwelling crustacean capable of reaching leg spans of nearly a meter and body weights over three kilograms. Juveniles use salvaged gastropod shells for protection, much like other hermit crabs, but adults develop a hardened exoskeleton over the abdomen and abandon shell-carrying entirely. They possess modified gill chambers that allow them to breathe air, and they will drown if submerged in water for extended periods.

Coconut crabs are omnivorous scavengers, feeding on fruit, carrion, and other invertebrates, and are known for their powerful claws capable of cracking open coconuts. They play a role in nutrient cycling and seed dispersal within island ecosystems.

The species is distributed across islands and coastal areas of the Indian and Pacific Oceans, inhabiting tropical forests, shrubland, rocky coastal zones, and supratidal marine habitats, from Madagascar and the Seychelles to Micronesia, Polynesia, and northern Australia.

Population decline is driven by overharvesting for food, a longstanding practice across much of its range, compounded by habitat loss from logging and coastal development. Roads fragment populations and cause direct mortality, while invasive predators threaten juveniles. Storms and coastal flooding degrade nesting and foraging habitat.

Conservation measures include harvest regulations and size limits in several jurisdictions, protected areas such as those on Christmas Island, and community-based management in parts of the Pacific. Enforcement remains inconsistent across its wide, fragmented range.

The population trend is currently decreasing, and the species is classified as Vulnerable. Continued harvesting pressure and habitat degradation suggest ongoing decline unless management measures are strengthened and consistently enforced across range states.