American Bird Conservancy (ABC), one of the nation’s leading bird conservation groups, today welcomed the decision by the U.S. Fish and Wildlife Service (FWS) to formally propose an Endangered Species Act (ESA) listing of ‘threatened’ for the highly imperiled rufa Red Knot, a shorebird which flies more than 9,300 miles from south to north every spring and repeats the trip in reverse every autumn, making this bird one of the longest-distance migrants in the animal kingdom.
Surveys of wintering knots along the coasts of southern Chile and Argentina and during spring migration in Delaware Bay on the U.S. coast indicated that a serious population decline occurred in the 2000s. Specifically, the 2011 count of the main wintering population of the bird in South America, found a decline from the previous winter of at least 5,000 birds—approximately one third of the population.
“There is a compelling scientific case for ESA listing. The U.S. Fish and Wildlife Service decision to list the rufa Red Knot, though long overdue, offers hope that future generations of Americans will be able to witness this migratory marvel,” said Darin Schroeder, Vice President of Conservation Advocacy for American Bird Conservancy.
Red Knot survival has been tied to battles over state and federal management practices associated with a key food source for the bird, horseshoe crab populations along the shores of New Jersey, Delaware, and Maryland. An abundant horseshoe crab population provides critical fuel for the bird’s migrations as they put on weight by stopping at Delaware Bay to feed on horseshoe crab eggs. Birds with higher weights have a better chance of reaching the Arctic to breed and survive into the next year.
In 2011, ABC organized a group meeting with FWS ESA Program staff, regarding ABC’s longstanding request to list the rufa Red Knot. Because of new information presented (including the 2011 count),FWS agreed to issue a proposed listing of the rufa Red Knot.
Despite this growing evidence of over exploitation of the horseshoe crab population, Atlantic States Marine Fish Commission has not the reduced harvest significantly in the last six years. Unfortunately, the Atlantic States Marine Fisheries Commission, which regulates the horseshoe crab harvest, dismantled its own shorebird technical committee after it recommended a moratorium on harvests.
Since 2005, four formal requests to list the Red Knot under the Endangered Species Act have been submitted to the FWS. Citing a lack of resources and other priorities, the Service chose not to list the bird but placed it on the candidate list in 2006. Since then, Red Knot numbers have continued to fall.
The decline of Red Knots and other shorebird species has been caused by a dramatically diminished supply of horseshoe crab eggs after millions of crabs were removed from the Bay beginning in the 1990s.
When Red Knots leave Delaware Bay in poor condition due to the lack of horseshoe crab eggs, they either die before ever arriving in the Arctic or arrive in too poor a condition to successfully reproduce. As a result, adult birds are dying off without being replaced by juveniles, leading to a decline in population.
Attempts to rebuild the Delaware Bay horseshoe crab population through minimal reductions in harvest quotas have to date been unsuccessful. The State of New Jersey implemented a moratorium on horseshoe crab harvesting in 2008.
Governments and scientists from five other countries where Red Knots breed, stopover, or winter are studying and working to address the other threats the species faces. At a meeting attended by many of the knot experts, they agreed that rebuilding the horseshoe crab population at Delaware Bay by implementing a moratorium until recovery occurs is the top management priority.
Red Knots are not the only species affected by the horseshoe crab fishery. Other species including Sanderlings, Ruddy Turnstones, and Semipalmated Sandpipers also depend on an abundant supply of horseshoe crab eggs at the Delaware Bay stopover. Each of these species has experienced significant declines, as well.
This article was written and published by American Bird Conservancy (ABC), a 501(c) not-for-profit membership organization whose mission is to conserve native birds and their habitats throughout the Americas. ABC acts by safeguarding the rarest species, conserving and restoring habitats, and reducing threats, while building capacity in the bird conservation movement.