Christmas Island Crabs Painting the Town Red : Nature: With the monsoons come 130 million crustaceans, which bury cars, cover bicycles and stain apartment walls red in their efforts to get to and from the sea to mate. They are unique to this Australian isle.

CHRISTMAS ISLAND, Australia — Cars vanish under a pile of struggling crabs as 130 million crustaceans crawl through the sleepy streets of this tiny Indian Ocean island on their way to the sea to spawn.

The monsoon has arrived in Christmas Island, home to 1,400 people, triggering the dreaded crab migration.

For two weeks, millions of crabs move as one in the long, wet summer afternoons, blanketing the roads and making their clumsy way across 33,840 acres of land from their rain-forest habitat to the ocean.

The sea in parts of this remote island, 224 miles south of Indonesia, turns milky white as the crabs spawn in one of the world’s more impressive natural displays.

“(Christmas Island is) right up there with the Galapagos archipelago in uniqueness,” said ranger Roger Hart of the Australian National Park and Wildlife Service, drawing a comparison with the islands off Ecuador renowned for their rich ecology.

“The whole business of crabs living in rain forests and living on vegetable matter--it’s not the sort of thing crabs are expected to do,” he said.

Christmas Island, a far-flung Australian territory 1,615 miles northwest of Perth, has a biology all its own which is only now being understood.

Over the million or so years since their arrival on the island, Gecarcoidea Natalis, or Christmas Island red crabs, have evolved large lungs and adapted to the lush jungles of the phosphate-rich island, girdled by steep sea cliffs.

Unique to the island, the crabs eat leaves, fruits and berries and remain close to the small burrows they make on the moist rain forest floor.

During dry spells they cover their abodes with foliage to hold in humidity and after a rainfall scamper out to scoop water into their mouths with their claws.

Urine from the base of their antennae washes over their bodies, keeping them cool, and nutrients are reabsorbed through the remnant gills.

It is the arrival of the monsoon that the islanders dread.

The frequent rains trigger the migration of millions of male crabs.

Thousands are crushed by passing cars and quickly gobbled up by their migrating brethren.

“When the adults migrate, you cannot avoid them,” said National Parks environmental scientist Holger Rumpff. “. . . They are everywhere on the island.”

The males cluster on rocks by the water, building burrows and dipping into the water while awaiting the females. Battles often erupt between competing males over space to build burrows in the tightly packed seashore.

The females arrive and the crabs mate in the burrows. Three weeks later, in the night and as the tide comes in, females make squeaking noises as they release up to 100,000 eggs each.

Later the eggs are cast into the sea, where over the next month they hatch into larvae and feed on sea plankton.

Once they have grown large enough to walk, billions of the tiny pink creatures begin the advance to land. Millions die in the attempt to reach the jungles--washed out to sea, eaten by fish and birds or crushed by cars and human feet.

“It’s impossible to walk or drive around them,” said Patricia Power, owner of the Arenga Palm Cafe. “You often can’t avoid running over them.”

Rangers close off roads along the major routes favored by the baby crabs, but the carnage is widespread. Chickens peck at the rolling red blankets of baby crabs, cats lap them up and millions crack and pop under foot.

The island golf club has even devised special rules to accommodate these migrations.

For days they flow like liquid over bicycles and gutters, scale the mosque and stain the apartment blocks in the Malay Kampong a writhing red. Depending on the tides, migrations to the jungle can occur six or seven times in one monsoon.

The crabs are not Christmas Island’s only unusual creatures. In the 10 million years since the volcanic isle rose from the sea, three unique bird species have evolved.

About 4,000 birds remain and they nest only in the western plateaus of the isle. A further five bird subspecies are unique to the island, such as hawk-owls, swiftlets and frigate birds.

First sighted in 1615, the uninhabited isle was claimed by Britain in 1888 and ruled from colonial Singapore before being transferred to Australia in 1958.