{"id":8703,"date":"2020-11-14T11:42:33","date_gmt":"2020-11-14T00:42:33","guid":{"rendered":"https:\/\/scienceillustrated.com.au\/blog\/?p=8703"},"modified":"2020-11-14T11:51:09","modified_gmt":"2020-11-14T00:51:09","slug":"why-do-christmas-island-crabs-swarm-every-year","status":"publish","type":"post","link":"https:\/\/scienceillustrated.com.au\/blog\/nature\/why-do-christmas-island-crabs-swarm-every-year\/","title":{"rendered":"Why do Christmas Island crabs swarm every year?"},"content":{"rendered":"<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-8704\" src=\"https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2020\/11\/crabs.jpg\" alt=\"Alamy\/Imageselect &amp; Jurgen Freund\/Ingo Arndt\/Nature PL\" width=\"1920\" height=\"858\" srcset=\"https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2020\/11\/crabs.jpg 1920w, https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2020\/11\/crabs-300x134.jpg 300w, https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2020\/11\/crabs-1024x458.jpg 1024w, https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2020\/11\/crabs-768x343.jpg 768w, https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2020\/11\/crabs-1536x686.jpg 1536w\" sizes=\"(max-width: 1920px) 100vw, 1920px\" \/><\/p>\n<p class=\"p1\">Once a year on Christmas Island, in the Indian Ocean, some 120 million terrestrial crabs migrate from the jungle to the water to breed. The crabs swarm during the rainy season, which takes place between<span class=\"Apple-converted-space\">\u00a0 <\/span>October and December. When the air is moist, the crabs are able to complete the 5-7 day trip without dying from dehydration.<\/p>\n<p class=\"p2\"><span class=\"s2\">The crabs mate on the beach in small holes <\/span>in the sand, then the males return to the rainforest while the females produce eggs. The eggs are then carried to the water\u2019s edge to coincide with the turning of the tide, <span class=\"s3\">the female releasing their eggs when the difference between ebb and flow is the least.<\/span><\/p>\n<p class=\"p2\">The eggs hatch immediately they come into contact with water, the small crabs developing in the ocean over a period of about one month, until they are 5mm wide. They then move back onto shore and begin a nine-day march back towards the rainforest.<\/p>\n<p class=\"p2\">As the crabs migrate across several of the island\u2019s roads, traffic is halted so that cars don\u2019t crush too many of the red crabs, and special pathways are provided across major roads.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-8709\" src=\"https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2020\/11\/crabsp.png\" alt=\"Alamy\/Imageselect &amp; Jurgen Freund\/Ingo Arndt\/Nature PL\" width=\"1726\" height=\"1764\" srcset=\"https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2020\/11\/crabsp.png 1726w, https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2020\/11\/crabsp-294x300.png 294w, https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2020\/11\/crabsp-1002x1024.png 1002w, https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2020\/11\/crabsp-768x785.png 768w, https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2020\/11\/crabsp-1503x1536.png 1503w, https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2020\/11\/crabsp-50x50.png 50w\" sizes=\"(max-width: 1726px) 100vw, 1726px\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Once a year on Christmas Island, in the Indian Ocean, some 120 million terrestrial crabs migrate from the jungle to the water to breed. The crabs swarm during the rainy season, which takes&#8230;<\/p>\n","protected":false},"author":15,"featured_media":8704,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7,52,32,6],"tags":[864,907,906,908],"class_list":["post-8703","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-animals","category-ask-us","category-marine-biology","category-nature","tag-australia","tag-christmas-island","tag-crabs","tag-migration"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/posts\/8703"}],"collection":[{"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/users\/15"}],"replies":[{"embeddable":true,"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/comments?post=8703"}],"version-history":[{"count":5,"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/posts\/8703\/revisions"}],"predecessor-version":[{"id":8710,"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/posts\/8703\/revisions\/8710"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/media\/8704"}],"wp:attachment":[{"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/media?parent=8703"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/categories?post=8703"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/tags?post=8703"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}