ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel
  • »
  • Education and Science»
  • Life Sciences»
  • Marine Biology»
  • Marine Life

The migrating red crabs

Updated on December 3, 2011
Baby red crabs
Baby red crabs | Source
Start of the red crab migration image copyright @ Christmas Island Tourism Association
Start of the red crab migration image copyright @ Christmas Island Tourism Association | Source

Have you ever wonder how it will be like standing in the middle of the road with millions of crabs crawling around you? That's what you will get if you are in Christmas Island in the middle of the red crabs migration.

This wonderful event happen but once every year when the crabs goes down to the sea to mate. The so called red crabs are land dwelling animals. They live in the rain forest on the mountains, burrowing holes in the soil and make the annual trip down to the sea for mating (and probably a bath too).

The migration starts around October/November when the wet season starts on the island. All the male will go down first in the first wave of migration, which takes roughly 2 weeks, followed by the female. The males fight out for the best spot in the beach and await the females to arrive.

When the migration starts, the road around the island is filled with stench from the dead crabs as they get squashed from vehicle on the road. Although the community has set up nets and created drains to ease the road kills, many still die in the annual event.

Once the female are full with eggs, they clung to the cliffs and dislodge their eggs into the ocean. This normally happen during high tides associated with the full moon. As with how the male migrate down to the sea first, they will also return back to the mountain in the first batch, while the female will return in the second wave. The eggs will develop in the ocean and will be washed back to the island when the tides are right. However, it is not every year that the baby crabs successfully return to island. Generally, we see the baby return once every five years. The baby crabs are really tiny - slightly bigger than the size of a big ant. They will also make the pilgrimage climb back to the mountain upon their return to land.

Currently, the red crabs are in danger from the introduced 'Crazy Ant' that is invading the island. They are killing the crabs as they spread around the island. The crabs are vulnerable to the crazy ant attack as the ants start attacking the eyes of the crabs and killing them. Steps have been taken to control the crazy ant population, however, none has been a successful story yet. Sadly, the crazy ants are winning the fight and have drastically reduced the population of the red crabs on the island.


    0 of 8192 characters used
    Post Comment

    • sweeaun profile image

      sweeaun 6 years ago from Malaysia

      Gosh, I wonder how many crabs will make it to the sea with all those obstacles along the way.

    • ssid profile image

      ssid 6 years ago from Australia

      zzron: i do agree it is one of the weirdest natural event.

      homesteadbound: the crazy ants are unfortunately adaptable to their introduced place. hopefully they can be stopped before they do more damage to the native wildlife.

    • homesteadbound profile image

      Cindy Murdoch 6 years ago from Texas

      We have fire ants where I live and they have played havoc with some of the native wildlife.

      This looks like it could be a very interesting event to observe.

    • zzron profile image

      zzron 6 years ago from Houston, TX.

      I have seen this on TV. It was the weirdest thing. Cars would just drive down the road squishing those little suckers like they were potato chips and not thinking twice about it. I have never seen such a thing.