Crabs
The island is particularly noted for its prodigious populations of Christmas Island red crabs (Gecarcoidea natalis), whose mass migrations at spawning time may number over a hundred million individuals. The bright red carapaces and sheer density of crabs make their routes to the sea observable from the air. Nonetheless, the populations of red crabs are threatened by the arrival of the invasive yellow crazy ant (Anoplolepis gracilipes). The ant was accidentally introduced between 1915 and 1934, and without any native ant species to compete against, rapidly formed 'supercolonies' of extremely high density. Populations of the ant have been observed bringing down red crabs over a hundred times their combined biomass. A. gracilipes is thought responsible for killing up to 30 million of the park's crabs.
While the red crab is Christmas Island's most numerous crab, the island also hosts the world's largest population of Coconut Crab (Birgus latro), the world's largest land invertebrate. There may be as many as one million coconut crabs on Christmas Island. It is also home to several species each of hermit crab, grapsids and gecarcinucoidea.
Read more about this topic: Christmas Island National Park, Flora & Fauna, Fauna
Famous quotes containing the word crabs:
“Baltimore lay very near the immense protein factory of Chesapeake Bay, and out of the bay it ate divinely. I well recall the time when prime hard crabs of the channel species, blue in color, at least eight inches in length along the shell, and with snow-white meat almost as firm as soap, were hawked in Hollins Street of Summer mornings at ten cents a dozen.”
—H.L. (Henry Lewis)