Paradise on the Delaware Bay
One of the wonders of
the world happens each spring on our beaches. With an act of timing that
only Nature can provide, horseshoe crabs climb up the beach to spawn and
shorebirds pause in their migration to feast on the horseshoe crab eggs.
A good place to start in your search for more information about this phenomenon
Here is a simplified explanation
of the event. At high tide, especially at the spring tides following the
full and new moons, male and female horseshoe crabs form "trains" with
a female in the lead and one or more smaller males attached behind. These
crab groups then come up onto the beach, the female lays and buries the
eggs and the male(s) fertilizes them. Gulls and the higher waves uncover
many of the eggs which get into the water and are deposited on the wrack
line on the beach (see the report of May 9, 1999
for a picture). Birds of many varieties, including millions of migrant
shorebirds, spend their spring days feasting on the eggs.
Lower Township has placed signs
along the beach to explain the phenomenon. Our top left and middle pictures
show those signs in Town Bank. The top right picture shows an undulating
group of sanderlings feasting on horseshoe crab eggs on a May morning.
At the lower left we see a female horseshoe crab helpless on her back.
Females are larger and their front legs terminate in a "scissors" type
of claw. In the lower middle picture we see a smaller male. The males have
a "grabber" type of claw at the end of their front pair of legs. At bottom
right is an upended couple. The male is tenaciously hanging onto the "pegs"
at the back of the female's shell. Males also have the "pegs" which allows
for longer "trains" of crabs.