In May of each year, Delaware becomes host to a bird in transit on one of the longest migrations in the animal kingdom.
The red knot flies from the southern tip of South America to the high Arctic, and it times its arrival in the Delaware Bay to coincide with the spawning of the horseshoe crab, a species older than the dinosaurs. Because replenishment on horseshoe crab eggs is essential for red knots to complete the final leg of their migration, the survival of the red knot is profoundly linked to a sufficient population of horseshoe crabs.
In Delaware, the spring migrational stopover for red knots ranges from Port Mahon to Cape Henlopen, with the peak numbers typically found near the middle of May. The highest concentration is found near the Mispillion Harbor, although there are other reliable observation spots. The Delaware Ornithological Society is hosting a shorebird watch on May 15 at the DuPont Nature Center at the Mispillion Harbor.
Horseshoe crab spawning is predictable and occurs at high tide on the nights of a full moon and new moon in May and June, although peak spawning is weather-dependent.
Because of years of unregulated horseshoe crab harvests in the Delaware Bay during the 1990s, the red knot population has declined more than 90% from its pre-overharvest levels.
Although New Jersey banned the horseshoe crab bait harvest, Delaware still maintains a harvest, in spite of the red knot being listed as threatened under the Endangered Species Act. Delaware Audubon is planning to work with other partners to promote a horseshoe crab bait harvest moratorium in Delaware to prevent further decline of the imperiled red knot.
Steve Cottrell
President, Delaware Audubon Society
