Species Profile: Red Knot

Working to Halt the Rapid Decline of the rufa Subspecies

Red Knot. Photo: T.D. Rodda

The Red Knot is a small, short-legged shorebird characterized by a rich, robin-red breast in breeding plumage. Worldwide, there are five subspecies of the Red Knot; the rufa subspecies is an extreme long-distance traveler, migrating 18,000 miles each year from its winter home in Argentina to the tundra of North America, where it nests—and back.

As rufa Red Knots journey up the east coast of the United States during their spring migration, they pause at ancestral stopping points to rest and refuel. Delaware Bay is the last and most important stop on this long journey. Knots are among the hundreds of thousands of migratory shorebirds that arrive just as horseshoe crabs are spawning to feast on the abundance of nutrient-rich crab eggs, in preparation for the last leg of their migration north.

In recent years, horseshoe crab numbers in Delaware Bay have been severely depleted by commercial fishermen who sell the crabs for use as bait in conch pots. With fewer female horseshoe crabs laying eggs, migrating knots are deprived of their primary food source and are thus unable to gain back the strength and body mass they need to finish their migration successfully. Birds that do manage to complete the journey often arrive at their breeding grounds weak and undernourished, and are therefore less likely to nest and reproduce successfully.

Scientists in both North and South America have noted alarming declines in rufa Red Knots resulting from an increase in horseshoe crab take in and around Delaware Bay. The decrease in horseshoe crab numbers has caused the knot population to decline by 80 percent over the past 10 years, leading ornithologists to predict that the subspecies will be extinct in as little as five years unless action is taken.

ABC has taken a leading role in the conservation of the rufa Red Knot. Among the recent successes have been a coast-wide reduction in crab take from New Jersey to North Carolina, a moratorium on crab fishing during the critical spawning period, and the creation of a horseshoe crab sanctuary at the mouth of Delaware Bay, off-limits to crab fishermen. ABC has also raised money for research on horseshoe crab population trends.

Despite all this conservation action, Red Knot numbers have continued to plummet. Although the declines of many bird species can be averted before they need to be listed under the Endangered Species Act (ESA), by July 2005 the Red Knot was running out of options. Consequently, ABC and other leading conservation groups (including Defenders of Wildlife, National Audubon Society, and New Jersey Audubon) filed a petition for the emergency listing of the rufa subspecies under the ESA. An immediate moratorium on the harvest of horseshoe crabs was also recommended. Unfortunately, FWS turned down this emergency listing appeal in January, but says it will continue reviewing the Red Knot’s status for possible listing in the future.

ABC continues to work with members of the Bird Conservation Alliance, including those named above, in pushing for greater protection for the Red Knot. Thanks to this pressure, the Atlantic States Marine Fisheries Commission is considering a proposal that would impose a two-year ban on the take of horseshoe crabs in New Jersey and Delaware. The passage of this proposal would be a major victory for this long distance traveler, whose future now depends on favorable policy decisions and the grit and determination of ABC, its partners, and members.