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Defenders Magazine
Red Knots in a Bind
Conservationists race to save these wandering shorebirds from extinction.
Their wings a blur as they flash low over the sand and the blue water of the Delaware Bay, the grayish birds turn, hundreds of fast-moving bodies whose rusty breasts catch the sun. These shorebirds, known as red knots, have just arrived from South America — their journey one of the iconic examples of global migration — and they are hungry. Without preamble, these robin-sized birds land and begin plunging their thin, black bills into the sand, probing for food. More and more arrive, until the beach is blanketed with more than a thousand of the tired travelers.
To a casual observer, this sight would be mesmerizing, even breathtaking. But to biologist Larry Niles, watching last spring along a curving beach just north of Cape May, New Jersey, it was only a poignant shadow of what once ranked among the greatest wildlife spectacles in North America. Until recently, more than a million and a half migrant shorebirds congregated on the beaches of the bay, feeding on the eggs of millions of spawning horseshoe crabs, the sand all but hidden beneath the seething mass of birds and the domed carapaces of the crabs.
But in the past few years commercial fishermen have eviscerated the crab population, and the number of shorebirds here has plunged. The red knot has suffered a decline so severe that some experts predict the population stopping over at the bay could be gone within five years. The situation is so grim that in July, Defenders of Wildlife and eight other organizations filed a petition with the U.S. Fish and Wildlife Service, asking that the agency take emergency action to list the bird as endangered.
For Niles, chief of New Jersey's endangered species program, the red knot's spiral toward extinction has been an intensely personal loss. It is a tragedy he has watched unfold not only in his own backyard along the shores of the Delaware Bay—one of the nation's richest marine estuaries, though often overshadowed by the larger, better-known Chesapeake Bay 75 miles to the west—but at the farthest corners of the hemisphere, in the Canadian Arctic and Tierra del Fuego, where for years he has followed this extraordinary bird on its annual travels.
Niles vividly remembers the days in the 1980s and early ‘90s, when more than 100,000 knots stopped on the bay each May and early June. He watched as the birds would tank up on trillions of eggs laid by millions of spawning horseshoe crabs, which generally come ashore at the highest tides of the month to dig their nests just above the waterline. "It's the soul of the Delaware Bay itself, the horseshoe crabs breeding," Niles says.
When Niles first began observing the birds, people took relatively small numbers of crabs for eel bait or for biomedical labs that collect crab blood as a medium for testing the purity of injectable drugs. In the early 1990s, however, commercial fishing operations began dredging enormous numbers of crabs to use as cheap bait for whelk (sold as conch) as well as eel. By 1998, these operations were removing 6.5 million pounds of crabs from the bay each year, landing them as far away as Virginia and New York to avoid emergency harvest quotas in Delaware and New Jersey. Regional quotas are now in place, but many experts feel the annual harvest, about 2.5 million pounds, is still unsustainable.
Defending Red Knots
Defenders of Wildlife is spearheading efforts to save red knots from extinction. Last summer, Defenders and other groups petitioned the federal government for an emergency listing of the bird under the Endangered Species Act. At press time, the government had not yet acted on the petition.
But in the meantime, Defenders and its allies have been pushing officials to curb fishing of Delaware Bay's horseshoe crabs, on whose eggs the red knot depends. In November, the Atlantic States Marine Fisheries Commission, the federal group that regulates such fishing, announced that it would consider a two-year moratorium on the take of horseshoe crabs in the state waters of New Jersey and Delaware, as well as restrictions on the take of horseshoe crabs in deeper waters of Delaware Bay by fishers from other states.
"The governors of New Jersey, Delaware, Maryland and New York and their departments of natural resources should be commended for their support of this much-needed action," says Caroline Kennedy, director of field conservation programs for Defenders. The commission is scheduled to meet later this winter to vote on the proposed moratorium and restrictions.
Horseshoe crabs are ancient and harmless creatures, more closely related to spiders than crustaceans, and they are slow to mature—requiring nine or 10 years to begin breeding. As millions of these animals have been removed from the bay each year, the supply of eggs available to birds has plummeted. Other species of shorebirds use the crab eggs as migratory fuel, but none is so dependent on them as the red knot, which is now suffering a population freefall. Annual surveys of knots on the Delaware Bay have shown a decline from more than 100,000 in 1989 to barely 13,000 in 2004. Research on the birds' wintering grounds in South America confirms the trend.
Niles and other experts agree that the subspecies of knots using Delaware Bay—which once comprised 80 percent of the hemisphere's red knot population—is in danger of extinction.
Even in the rarified world of long-distance migrants, the red knot is a standout. Almost all of North America's red knots belong to the subspecies Calidris canutus rufa. Most of these birds make an arduous 18,000-mile-per-year migration between the southern tip of South America and the Canadian Arctic. They traverse the distance in a few nonstop flights that may stretch thousands of miles—from southern Brazil to the mid-Atlantic coast, for example, and then another long hop to the Arctic. Both sexes arrive in bright, brick-orange breeding plumage that explains one old folk name, "robin snipe."
To accomplish such a migratory miracle, the birds need fat to burn as fuel. That means finding food in huge and predictable quantities—something the horseshoe crabs of the Delaware Bay once supplied. A single red knot, consuming as many as 18,000 eggs a day, could double its weight in about two weeks. This fat is crucial not only for its flight, but to carry the bird through the first harsh weeks on its breeding grounds in Canada, when the land often remains locked in snow and ice. Without the bay's largess, the knots cannot hope to complete the trip and raise a family in the unforgiving Arctic.
The red knot faces extraordinary challenges at every phase of its life cycle—something Niles says he and his colleagues didn't really appreciate until they started following the bird throughout the year. In Tierra del Fuego, where many knots spend our winters (it's summer, at least nominally, at that latitude), the researchers were buffeted by blinding gales that blew up without warning, and tides that surged 25 and 35 feet every 12 hours. It is a vast landscape that dwarfs humans—and so did the number of knots.
"When we first went down to Tierra del Fuego, we would see flocks of knots so big that the roar of wings would sound like aircraft going over—flocks of 20,000 birds at a shot. And now we're at a point where there may only be 20,000 knots, and the biggest flock we saw this past year was about 3,000 birds," he says. Winter surveys suggest a third of the population disappeared in 2004 alone.
The challenges facing the knots are even greater on the Arctic nesting grounds. In 2004, Niles's study area on Southampton Island was hit with a July 3 snowstorm that wiped out the eggs, not just of the knots, but all the nesting birds in the area.
"It's a very harsh environment," Niles says. "In the normal sequence of things, these birds would be lucky to get two good seasons out of five, because of all the uncertainty of the Arctic." But now even the good seasons are in jeopardy, if the birds arrive underweight from not finding enough crab eggs. In 2003 the Arctic summer was mild and favorable, but because the crab spawn was poor in the Delaware Bay, the knots arrived thin and out of condition, and raised almost no chicks.
That's why it's essential that the U.S. Fish and Wildlife Service move quickly to list the red knot as endangered, says Caroline Kennedy, director of conservation initiatives for Defenders of Wildlife. Listing should give wildlife managers more of a voice in horseshoe crab harvests, which both Niles and Kennedy believe should have been closed years ago.
One problem, Niles says, is that the agency responsible for managing the crabs—the federal Atlantic States Marine Fisheries Commission—has no mandate to take the needs of birds into account. Likewise, the agency with responsibility for wild birds, the U.S. Fish and Wildlife Service, has no authority to set fishing quotas.
"A listing will solve that problem," Niles says. "It'll give more authority to the Fish and Wildlife Service and ultimately to the states to do something meaningful." One potential solution is for the government to buy out the crab fishers, given the small number of operators involved. New Jersey issues 30 crabbing licenses, but 90 percent of the crabs are harvested by just five fishermen, Niles says. The proportion is similar in Delaware waters.
At this point, all eyes are on the Department of the Interior, which could act on the emergency petition at any moment. If the department lists the knot, Larry Niles believes, there is still time to save the bird, restore the crabs and allow a resurgence of their once-spectacular union on the bay. [Editor's note: In early January, the Bush administration denied the request from Defenders of Wildlife and others to provide Endangered Species Act protections for the red knot. See the press release for more information.]
"We need to increase the availability of eggs to the birds, and the fastest way of doing that is to control the harvest—we're losing close to 400,000, 500,000 crabs a year," Niles says. "I think that if we further cut the harvest, there's enough leeway there for us to reverse the situation." But it may take a decade for the downward trend in crabs to reverse itself, Niles points out, so it is crucial to protect and improve other red knot stopover sites along the Atlantic coast, especially national wildlife refuges that include stretches of shoreline. One mile-long stretch of refuge beach near Stone Harbor, New Jersey, closed to the public, held 20,000 southbound knots in 2004.
"But first we have to take care of business on the Delaware Bay," Niles adds. "It's not just about the knots, it's not just about the shorebirds, it's not just about the horseshoe crabs. It's the bay. We need to fix it so we can bring the bay back to its proper health, for the good of people as well as animals. If we act now, we can save it, and we can save it in all its glory, so that 15, 20 years from now people will be talking about it just as they used to. And I think that's what all of our eyes are on right now, the next generation."
