COOK'S BEACH, N.J. — The small bird sitting along this sandy spit of land is starving and dinner offerings are slim.

Having flown 5,000 miles from South America and with 5,000 to go to its Arctic breeding ground, the red knot needs to fatten up along Delaware Bay or die. For tens of thousands of birds over the last decade, death has been inevitable. The red knot population, scientists believe, may be down to its last 25,000.

Two weeks ago, bird experts and environmentalists called on the federal government to accelerate the review process for placing the red knot on the endangered species list. The U.S. Fish and Wildlife Service has proposed a schedule that could begin as early as this fall.

Those same groups urged Maryland and Virginia to ban the commercial harvesting of horseshoe crabs, whose fat-filled eggs are the primary food source for the red knots as they migrate north but are no longer abundant.

"What Maryland is doing is not scientifically defensible from our perspective. Maryland is part of the problem," said Caroline Kennedy, vice president of the Defenders of Wildlife. "We need a moratorium."

Maryland fisheries officials say they have reduced harvests, especially of female horseshoe crabs, and put the crabs off limits for the first six months of the year to protect spawning adults.

"We feel we are managing crabs for a sustainable population," said Mike Luisi of the Department of Natural Resources.

The Atlantic States Marine Fisheries Commission, the primary authority overseeing the health of horseshoe crabs, is updating a plan to provide options for a Delaware Bay management program. The commission's horseshoe crab experts will be meeting in Annapolis on June 24.

Wave-side feast

Each May, an international team of biologists and birders gathers at this ramshackle house on Delaware Bay just north of Cape May to capture red knots in an attempt to understand the birds' decline and, perhaps, reverse it.

With evidence of stormy May weather on the horizon, the team gathered anxiously behind a sand berm, waiting for the "pop" of a small cannon that released a net to capture several hundred birds feeding near the waterline.

Men and women dashed from cover, plucked the birds from the netting and began separating them by species to get blood and feather samples and to band them for identification in the Arctic and in South America. Some birds are outfitted with geolocators to track their flights.

Their concern goes beyond red knots. Many migrating shorebirds — sanderlings, ruddy turnstones and semipalmated sandpipers — also rely on horseshoe crab eggs to energize them for the breeding season to come. The number of those birds has "declined significantly," said Kennedy as she helped with the sorting.

As home to one of the world's largest populations of horseshoe crabs, Delaware Bay had long been a gigantic bird feeder for red knots. In mid- to late-May, migrating red knots — about the size of robins — show up famished, weighing about half their normal weight. For a week or so, they gorge all day long on BB-sized horseshoe crab eggs, each consuming 18,000 or more, until their weight doubles to give them the fuel needed to fly nonstop to the Arctic.

But in the mid- and late-1990s, commercial fishermen scooped up millions of horseshoe crabs to sell to the bait industry, using pitchforks and snow shovels to pile the helmet-shaped creatures into pickup trucks. At the height of the harvest, more than 2 million crabs a year were being taken in the Middle Atlantic states.

By 1997, regulators finally stepped in, but the damage was done. A horseshoe crab takes nine to 13 years to reach sexual maturity so although the population is stable, it's in no position to feed the red knot.

As a result, scientists and birders who used to see 100,000 red knots feeding on the Delaware Bay in the 1980s saw a rapid decline. In 2001, they counted 45,000 birds passing through. Five years later, the count was down to 15,000.

Scientists say fewer and fewer red knots are making weight before their biological clock tells them to head north. The malnourished birds are no match for harsh Arctic conditions.

In August 2006, the red knot was designated a candidate for possible addition to the federal list of endangered species. It hasn't made any progress on a list that now numbers 251 species.