Cuba: Wild Island of the Caribbean
Cuban Crab Invasion

Each spring millions of small reddish land crabs emerge from the moist forests surrounding Cuba’s Bay of Pigs to breed in the nearby sea. As NATURE’s Cuba: Wild Island of the Caribbean shows, the evening invasions — which last for weeks — can wreak havoc on ordinary life. Roads become covered with smelly smashed crabs, while car owners must repair tires shredded by the sharp shells.

The crabs and their eggs do provide a feast for birds, fish, and some hungry mammals. But seafood-loving Cubans won’t touch them — they contain a harmful toxin.

More than four million years ago, the ancestor of these crabs — known to scientists as Gecarcoidea — lived in the sea. Slowly, however, they evolved to survive in a foreign place: the shady forest floor. But, like marine crabs, red land crabs still breathe with gills that must remain moist. To stay damp, the crabs dig tunnels. During the spring rains, males and females seek each other out and mate.

A few weeks later, the female crabs, swollen with eggs carried in a pouch, head for the nearby sea. The journey, which may be as long as six miles, can take days. And there are plenty of obstacles, such as roads, curbs, and even coastal resort swimming pools. On sunny days, the crabs must find shade — or dehydrate and die.

Those that reach the sea face one last challenge — laying their eggs while avoiding being swept back into the water. These crabs are true land creatures and cannot survive in the sea. Once the ripe eggs are successfully released into the water, they hatch immediately. After a few weeks, the baby crabs climb back onto land and head for the forests, to begin the cycle anew.

Cuba isn’t the only island to experience crab invasions. Related land crabs live throughout the Caribbean. And a similar species takes over Christmas Island in the Indian Ocean each fall.

There, an estimated 100 million red crabs move to the shores for a little romance. The males go first, taking up to several weeks to reach the surf, where they tenaciously fight for the best territory. The females follow, to mate with the males, and several weeks later are swollen with eggs. As on Cuba, the eggs hatch on contact with water, and the baby crabs make the return trip to the forests a few weeks later.

On both islands, officials make efforts to protect the crabs by closing some roads and sidewalks to create “crab crossings.” In part, that’s because the great crab migrations have become an unusual tourist draw. For some people, a glimpse of thousands of crabs scrambling into the surf is an unforgettable sight of a lifetime.

  • Noah Hogan

    I was shocked & saddened to see all those poor, helpless crabs getting crushed on the roads! In my GIS class, I’m going to make a map of their annual migration from the Bay of Pigs to the sea to help them!!!

  • elsa

    That was the worst part of our recent trip in Cuba, a real nightmare come true! Apart from the flat tire, the massacre of those poor animals was way too much for our nerves and stomach! I strongly advise you to avoid the area at breeding season, and I wish the Cuban tourist authorities do something about it. Underground pipes crossing the road would save the lives of million creatures!

  • Yvon Josaphat

    Government Officials should have a way to help the land crabs. It is very sad to see how the crabs have been crushed under the tires of those trucks. I hope somebody or organization can find a way to help them to continuing their journey.
    Thanks in advance

  • Rene Genest

    From our point of view of course it may look horrible to see many of them crushed under the truck’s tires, but if for us this crab movement is seen as a wonderful nature event, and it is, for cuban it may be seen as a million of varmit. How would we think if it had to happend here but with millon of rats…
    One day I will manage to get there and see it.

  • JJ

    Dude, forget that. Have a mass-cookout on the darn things. It’s not like they won’t come back in numbers the following year. I would pay to-dollar to eat these suckers, with a cuban cigar on the side.

  • Daniel

    JJ, the crab is toxic, you should charge the 2 dollars, at least.

  • Irina

    Don’t eat them, these land crabs are toxic. and…. Try to avoid killing them, they are part of nature, part of Life . :)

  • T1240

    Having recently witnessed this event, pipes are no solution. The crabs are crossing everywhere and you’d need thousands of pipes. A better solution would be an intervention to captive release either eggs or young to account for the numbers killed by human action.

    At the moment, those roads have little traffic. As Cuba follows the rest of the world, this will end up being a slaughter.
    :¬(

  • Grady

    GET A LIFE! These crabs are nothing more than a nuisance. Would you have these feelings if it was rats? These creatures serve no purpose other than giving a few tree huggers something to blog about. The only thing I can say is that its a good thing that they are toxic, or else we would have a feast with a cigar! Again, Get a Life!

  • kelsey

    Grady, JJ YOU ARE UNCARING JERKS!!!!! How would feel if someone ran over you. The land crabs are here for a reason, now we may not know that reason, but you could have a little room in your heart to care. some of us and the crabs don’t think that they are “a nuisance.” So shut up and care

  • akbill

    i know these crab personally, they make great baittfor fishing or some flatshovels and bucket for chumming

  • yves

    it s too bad!! there must be a way if not ,we should find a way to take the toxin right out and eat the f…g crab Hummm what a feast !!! with a cigar and of course a good anejo especial ron!!por favor!!

  • richardparker

    I know it seems bad. But we learned about this in my tropical ecology class and the cars arent actually killing enough of them to affect the population. It is easily offset by the huge amount of offspring they spawn each year. Doesnt make it any easier to watch though.

  • CAIBARIENENSE

    I was borne and raised in Caibarien Las Villas Cuba, is my knowledge and experience that most of us from Caibarien and neighboring town of Remedios have been eating the local land crabs for years and a toxic
    land crab had never been an issue.??

  • tony

    I would like to find more information about toxin in Cuban land crabs, In Caibarien Las Villas Cuba the people eat the local land crabs??

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