The red knot is one of the “other” winter shorebirds that most people couldn’t pick out in the Lowcountry tidewash.

To comment

Public comments on inclusion of the red knot on the federal Endangered Species list can be made at or Public Comments Processing, Attn: FWS–R5–ES–2013–0097; Division of Policy and Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, Suite 222; Arlington, VA, 22203.

So maybe it helps to know that the rust-breasted bird — the size of a robin — flew here from the Arctic and might keep going as far as Cape Horn in South America — a trip that over the course of a bird’s lifetime would be as far as the moon.

The red knot

One of the largest and most colorful “peeps,” or sandpipers.

Males perform high aerial displays while singing during courtship.

Can travel nearly 10,000 miles in a yearly winter migration from the Arctic to Tierra Del Fuego, Argentina.

Concentrate in huge numbers at traditional staging grounds during migration, where they feed on horseshoe crab eggs and are vulnerable to mass deaths. It’s been estimated that nearly 90 percent of the Eastern Seaboard population can be present on the Chesapeake Bay during a single day.

Cornell Lab of Ornithology, National Audubon Society

The red knot is disappearing, and its survival might just depend on horseshoe crabs — which are harvested for medicine.

Those are the reasons why it’s important that the bird has just been proposed for the federal Endangered Species list.

Maybe most importantly, beaches in the Lowcountry and along the Southeast coast are among the few places where the birds’ numbers appear to be growing.

If a beach were declared critical habitat for the red knot, what’s restricted there wouldn’t change much: The critical habitats almost certainly would be mostly the same spots already declared critical for the piping plover and sea turtles, according to the U.S. Fish and Wildlife Service.

But it would raise the bar somewhat for coastal communities controlling unleashed dogs and other threats, said Nathan Dias of the Cape Romain Bird Observatory.

Horseshoe crabs are another matter.

Red knots have declined by as much as 75 percent on the Eastern Seaboard since the 1980s, according to the Center for Biological Diversity, an environmental advocate. The decline has been tied to the decline of horseshoe crabs. The crab’s eggs are a vital food source to the long-ranging migrant, which has to double its weight while in the Southeast. Harvest of the crab has increased dramatically since the 1980s because it’s eel and whelk bait, and because it’s become invaluable medicine. An extract from the crab helps keep medicines and medical gear free from bacterial contamination. No other product is more reliable, according to Eric Lacy, the marine biomedicine and environmental sciences center director at the Medical University of South Carolina.

Surveys and studies now indicate that a few thousand red knots each year fly in from the Arctic and go no farther than the beaches in South Carolina, Georgia and Florida. Nobody knows if this is a recent occurrence or if it was happening all along, Dias said.

In the Lowcountry, the crabs are harvested by the thousands each spring spawning season. The crabs are a protected species here but not a threatened one. They are “extremely regulated,” said Sgt. Angus MacBride of S.C. Department of Natural Resources in an interview earlier this year.

“It could add to the concern” for the crabs if the red knot is declared endangered, Dias said.

Public comments on including the red knot on the Endangered Species list will be taken until Nov. 29.

Reach Bo Petersen at 937-5744, @bopete on twitter or Bo Petersen Reporting on Facebook.