Christmas Island Red Crab Migration



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Podobny obrazAdult red crabs begin their breeding migration to the sea as soon as the wet season starts and can last up to 18 days. This proces is fixed around the phases of the moon. If there isn't enough time for individual parts of their migration, they will delay the start. Female Red Crabs release eggs into the sea precisely at the turn of the high tide during the last quarter of the moon. The eggs hatch immediately on contact with the sea water. After about a month in the ocean, "Crab babies" gather  and leave the water.




Podobny obrazNumerous humans activities contribute to increased mortality among Red Crabs. The most common cause is crushing by vehicles. For these reasons, "crab crossing" are being constructed on roads which cross main crab migrations. Chief Ranger Muller and his team are currently helping 50 million crabs on their annual migration. They have spent months for preparing more than 20 kilometres of plastic barriers, 31 crab underpasses and five metre-high crab bridge, which have become tourist attractions.


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Links:
 http://www.environment.gov.au/resource/red-crabs-and-migration-christmas-island-national-park
 https://www.christmas.net.au/experiences/red-crab-migration.html
 http://www.telegraph.co.uk/news/worldnews/australiaandthepacific/australia/12045930/Crabs-get-their-own-bridge-to-cross-busy-road-on-Christmas-Island.html

Komentarze

  1. englishdiary18 grudnia 2017 12:54

    What is the strange phenomenon here? Crabs migrating isn't unusual. Unless you meant the spectacular appearance of the rock in the photos?

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