Red Knots and Horseshoe Crabs

Red Knots by Ralph Wright

Red Knots by Wright


The Challenge

The rufa Red Knot is included on the United States Watchlist of Birds of Conservation Concern and is a candidate for listing under the Endangered Species Act. It relies on the eggs of horseshoe crabs for food when it stops in Delaware Bay to refuel during spring migration from Argentina to Canada to breed – a relationship that goes back millennia. Unfortunately, those eggs are disappearing due to the overharvesting of horseshoe crabs, which are used as bait in conch and eel pots. Without a sufficient supply of eggs, many birds fail to complete their epic journey. As the horseshoe crab population has declined, so has that of the Red Knot.


ABC Conservation Framework

This program falls under the category of Eliminating Threats in ABC's Conservation Framework
pyramid icon


Primary Birds Impacted

The rufa subspecies of the Red Knot



The extinction of the Red Knot is preventable by ensuring an overabundance of horseshoe crab eggs in Delaware Bay when the birds arrive each spring. Restrictions on horseshoe crab fishing are needed to bring their numbers back to historic levels. The Atlantic States Marine Fisheries Commission, which regulates horseshoe crab harvest, has demonstrated an unwillingness to help the Red Knot above the financial interests of a few fishermen. Individual states such as Maryland have instituted some harvest limits, but ultimately, listing of the Red Knot under the Endangered Species Act is necessary to prevent its extinction.

ABC Results

ABC Results Button In February 2009, American Bird Conservancy  helped win a restriction on the take of horseshoe crabs in Maryland. Two male crabs must be taken for every one female, resulting in fewer crabs being taken in total—and more females surviving to lay their eggs on the beaches.
ABC Results Button Thanks, in part, to ABC, the rufa Red Knot was added to the Candidate List for future protection under the Endangered Species Act, indicating that government experts recognize the need to protect this species.
ABC Results Button Following the efforts of ABC and its partners, a sanctuary was established at the mouth of the Delaware Bay, within which horseshoe crabs may not be harvested.
ABC Results Button ABC helped pilot a giveaway program of horseshoe crab bait bags that reduce the need for horsesho crabs by up to 50%. Read More Here.


What Next?

What Next Button The Red Knot should be listed under the Endangered Species Act, thus providing its protection and the funding necessary to ensure its survival. Read More Here.
What Next Button Greater restrictions should be implemented in all states along the Atlantic seaboard, including Delaware, Maryland, New Jersey, and New York. ABC is pursuing a total ban on the take of horseshoe crabs until the Red Knot has recovered.

Take Action

Write to the director of the U.S. Fish and Wildlife Service to request that the Red Knot be added to the Endangered Species Act this year. ACT NOW.