Finally, wildlife advocates say, a small shorebird is getting the attention it so desperately needs.

Since 2005, four formal requests to list the bird, the red knot, as a federally threatened or endangered species have been submitted to the U.S. Fish and Wildlife Service.

In 2006, the service took initial action, placing the bird on the list of "candidate" species -- a kind of holding pattern for species it has concluded might warrant protection. But until funds become available for the time-consuming formal listing process, that's where they sit.

Now, the service is moving to list the red knot, a process that likely will take until 2013, a spokesman for the agency said. It involves preparing a proposed "rule," having a public comment period, analyzing the public comment and issuing a final rule.

Overall, the service announced today that it was "further strengthening a work plan" to focus its resources on many species in need of protection, as part of an agreement with a plaintiff group. The candidate list currently has 251 species.

"Finally, we have the process kicking in," said Eric Stiles, New Jersey Audubon's vice president for conservation and stewardship. "We applaud that. We know the Endangered Species Act works. It is literally the safety net for species."

Advocates say the listing would help not only the red knot, but many other shorebird species that migrate through Delaware Bay and are in a similar, although less dire, decline. These would include the ruddy turnstone, semi-palmated sandpiper and sanderling.

The red knot has one of the longest migrations on the planet. Each spring, it stops for refueling at Delaware Bay, where horseshoe crabs are just then coming ashore to lay their fat-rich eggs, a vital food for the bird.

But the bird's numbers have declined sharply in the past decade, roughly around the same time that harvests of the crab increased.  The crab is used as bait for conch, a delicacy in Asia. Whiel the crab itself is not in trouble, its numbers have declined enough to result in an egg shortage for the birds, biologists say. Harvest restrictions have been enacted, but not enough, the biologists say.

During the 1980s and '90s, peak Delaware Bay counts of the red knot reached 95,000.  Since 2004, they ahve been consistently below 16,000.  Likewise, in their wintering area at the tip of South America, peak counts have dropped from 75,000 to 16,260 in 2010.  At the winter count earlier this year, the number had declined to less than 10,000.

Meanwhile, a recent study by New Jersey biologist Larry Niles, who has followed the bird to the ends of the earth in a decade or more of study, and others has confirmed the key role that horseshoe crab eggs play.

"Right now, we need to see more adult crabs breeding, and we're not," Niles said. Fisheries officials that govern the crab harvest keep saying to give it more time, he said. "That would be fine, except we were promised signs of recovery six years ago."

He suspects further restrictions in the harvest are needed. Or the problem now may lie elsewhere. The illegal harvet may be greater than estimated. The blood of the crab is used as an indicator for contamination in medical devices, and the crabs are caught, partially bled and then returned to the wild. But a recent study suggested that mortality from this may be higher than estimated.

"The insistence that we wait and see means we're not dealing with these other problems," Niles said.

If the bird is listed, protection could be extended to the red knot's "critical habitat," which would include many barrier islands along the eastern seaboard. But none, perhaps, as important as Delaware Bay, which 25 years ago was designated as the first "site of hemispheric importance" by the Western Hemisphere Shorebird Reserve Network.

Historically, so many birds have converged on the area each spring that they almost obscure the landscape. Even now, some refer to the area as the nation's Serengeti -- a reference to the plains that host huge wildlife migrations in East Africa. The bay spectacle is credited with generating millions of dollars in nature tourism revenues. But many biologists fear a grim outcome. They are taking their children to see it before it disappears.

Click here to read Niles' series of blog postings about red knot work on the Delaware Bay this past spring.