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October 19, 2017

Christmas Island red crab

This Christmas Island red crab (Gecarcoidea natalis) is one of millions that inhabit the island in the Indian Ocean. Although fully terrestrial, millions of the crabs emerge at the same time for an annual mass migration to the sea to lay their eggs, halting road traffic and covering the ground in a thick carpet of crabs.

[Research supported by a U.S. National Science Foundation Graduate Research Fellowship (grant DGE 0646086).]

This research was detailed in the National Geographic television program "Great Migrations" in the episode titled "Born to Move." (Date image taken: October-December 2008; date originally posted to NSF Multimedia Gallery: Oct. 19, 2017)

Credit: Allison Shaw, Princeton University

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