Christmas Island is a unique natural habitat located in the Indian Ocean with many endemic species. The national park covers two-thirds of the island, which has been referred to as the Galapagos of the Indian Ocean.

Many people are aware of the red crabs whose mass migration to the sea has been described as one of the wonders of the natural world. Christmas Island has many other species of crabs, including the impressive robber crabs (Gecarcoidea natalis). These may be the largest land-dwelling arthropod on Earth.

Together these abundant land crabs clear the forests of leaf litter and maintain burrows that prevent soil becoming compacted, creating an open and diverse forest.

This thriving natural system, however, was disrupted by an invasive ...