In spring, about this time of year, Horseshoe Crabs move the sandy shoreline of beaches and islands along the Atlantic coast to spawn.  These odd creatures are relics from the past.  The fossil record indicates they have been on this earth for 300 to 450 million years, from the time when dinosaurs roamed, and they have persisted ever since. 

Delaware Bay supports the greatest concentration. And it's no coincidence that Delaware Bay is one of the major spring migration stopovers for Arctic-breeding shorebirds.  The eggs of Horseshoe Crabs are rich in fats that help shorebirds replenish the essential fat that will fuel their next leg of migration which, for many species, will carry them to Arctic breeding grounds.

On the shores of Delaware Bay about a week ago, I was on the beach about the time of high tide and late afternoon, when Horseshoe Crabs emerged to spawn. Thousands of them lined the shore.  Females depositing their egg masses in the wet sand; males surrounding the females to fertilize the eggs as they were laid. And it's hard to imagine that these ancient creatures have survived and this ritual of life persists.  

In another post, I will talk about some of the challenges for the crabs and species that depend on them.