The Food Web by the Delaware Beach Adapted from: Horseshoe Crabs and Shorebirds: The Story of a Food Web by Victoria Crenson
It was in spring when the horseshoe crab migration began. Slowly crawling along the seafloor they make their way to shore to lay their eggs.
As the sun sets beneath the horizon, thousands of horseshoe crabs slowly crawl onto the beach in pairs, one male and one female. The female burrows into the sand to lay her eggs while the male tags behind to fertilize them. The female digs several nests and drop clutches of her eggs in each nest. Each night, the horseshoe crabs repeat the routine to lay more eggs.
By morning, some of the eggs have been exposed on the beach from their nests due to the waves. A blackbird sweeps down to gobble the eggs. Up into the air she flies and back to her nests to feed her hatchlings. Next, a flock of seagulls come to pick at the eggs. Finally a huge flock of shorebirds arrive to feast on the horseshoe crab eggs.
Suddenly a huge falcon swoops down from the sky and grabbed one of the flying shorebirds. The falcon squeezes her talons into the shorebird and the little bird goes limp. The falcon perches at the top of an old tower to feast on her prey. The predator will return for more.
Some of the horseshoe crab eggs have been washed into the sea and into a nearby creek. Large schools of minnows begin to feed on the floating eggs. Their movement attracts another a heron. The heron wades slowly towards the minnows and in a flash lunges her snaky neck. In an instant, the heron flips the fish into its beak and swallows it whole.
As night fell, the birds disappeared back to their nests and once
again the horseshoe crabs crawl up the beaches. That night there was a storm. By morning, some of the horseshoe crabs were upturned. The seagulls took this opportunity to feast on crab flesh.
Every day, from dawn to dusk, the feasting happens until autumn comes and the birds migrate to warmer places. Yet many of the eggs survived. Then, one night, the remaining eggs hatch. The tiny horseshoe crab larva crawls into the sea and are swept away by the waves.
In the water, the horseshoe crab larva grows and grows. After 10 years, it is finally an adult. Now it was time, for the horseshoe crab to go back to that same beach to lay its own batch of eggs.