Land Crab Migration
experience what National Geographic calls "one of the most incredible events in nature"
You have probably noticed lots of 8 inch high bands of green polycarbonate plastic along paths and rooms at Playa Escondida.
These are “crab barriers” designed to help guide our local land crabs through the maze of our resort without disturbing them.
After millions of years with their essential niche in this ecosystem we try to respect their importance and not inconvenience them during their relentless quest to reach the beach for their mating season.
The month of May is when you are most likely to see this huge migration.
If you are here during one of the days when they march en masse toward the beach you’ll witness an unforgettable spectacle of nature.
The jungle comes alive with thousands of crabs rustling through the leaves and brush on their determined race to the beach to stake out their mating territories.
Most guests find them fascinating but, for those who are uneasy about crustaceans sometimes entering their rooms, you should know they are harmless, and when they enter the houses it is only because they are lost on their way to the beach.
If you hear a loud scratching noise in the night it is probably a crab that has fallen into a wastebasket or sink and is trying to crawl out.
You can sweep them out to help them on their way. They like to eat hand soap and also you should be aware that they have been known to carry away small objects like earrings!
Our crabs, crustaceans of the Gecarcinidae family, burrow to the water table in the hills as far as several miles from the shore during the dry season. When they sense the approach of the rainy season they migrate to the beach where they await conditions for reproduction.
The land crab is in a stage of evolution where they have left the ocean but depend on it for reproduction. They are in constant danger of dehydration when they are away from water, as they still breathe with gills.
In their migration, which at times can be spectacular with millions of crabs marching toward the sea, they blindly climb over whatever is in their path. Instinct guides them to the shore where they burrow into the sand to protect themselves from sun and ocean.
Although they die if swept into the ocean, they must shed their larvae into the salt water to reproduce.
This is usually done at time of the full moon when the female inches her way to the edge of the surf then vigorously shakes her body to throw off the tiny eggs which immediately begin to hatch.
About two weeks later the baby crabs emerge from the ocean and start their march toward the hills while the adults remain for several breeding cycles until the end of the rainy season.
There is a tremendous mortality rate for both young and old crabs as they are in the food chain for many fish, birds and land animals and many are lost as road kill. We try to protect them from human caused mortality.