Help the Delmarva Ornithological Society Help the Red Knot

Red Knots have become the poster child for declining shorebird populations around the globe. This individual, photographed at Mispillon Harbor, Delaware on 27 May 2007, sports coded green leg flags and a U.S. Fish and Wildlife Service silver leg band (right leg). The colorful flags allow biologists and researchers to relocate and identify it from among the thousands of other knots migrating north along the Atlantic Coast each Spring. (Photo taken by Chris Bennett)

There is a dispassionate way to think of the Red Knot, the robin-sized shorebird which flocks to the Delaware Bay every year in May and June on the way to its Arctic breeding grounds.  If your concern is correctly identifying it, you could look in your eastern Peterson guide (Fifth edition) and read about how it looks during the breeding season:  “Face and underparts pale robin red; back mottled with black, gray, and russet.”  In case you weren’t sure that you were in Red Knot habitat, you could check your Peterson guide for that, too:  “Sandy beaches, mudflats, tidal flats and shores; breeds on tundra.”  If you wanted to delve a little deeper, your Peterson would tell you that the knot is a “well-studied species that has very specific stopping spots for feeding and staging during migration.”

Very specific stopping spots? This is not an overstatement.  Let’s say you’re not a birder, but a member of the rufa subspecies of the Red Knot, the particular variety of knot that flies up the Atlantic coast (destination:  Arctic tundra) as spring unfolds each year.  Most likely you winter in the Southern Hemisphere, in Tierra del Fuego, with about 15,000 of your fellows, although you might be part of a 50 percent smaller population which shares a stretch of beach in northern Brazil at Maranhao, or a member of a yet smaller group on Florida’s Gulf Coast or the relatively short Georgia shoreline.

It’s been a tough winter as you search for your usual food, hard-shelled bivalves (such as the blue mussel), along South American beaches often favored by people on vacation. You may find yourself near offshore oil rigs which have been known to spill their black muck into the very water you rely on to yield sustenance.  If you’re wintering in the southeastern U.S., you face similar challenges.  But spring approaches and it’s time to move north over thousands of miles to your chief re-fueling stop before hitting Canada’s Hudson Bay and beyond, and you can’t wait.  The Delaware Bay beckons, with its feast of tiny, translucent eggs laid by dull-brown, prehistoric arthropods called horseshoe crabs.  These creatures are shaped like a shallow helmet and about the size of one, too.  Their other notable feature is a long, narrow, dark tail that tapers to a sharp point.  When the crabs come ashore to mate and lay their millions of eggs, they will seem to fairly cover the Bay beaches they favor (rough ocean-side waves would just wash the eggs out to sea).

What’s the big deal about the unimpressive-looking beads of fat and energy laid by the crabs?  You, the Red Knot, have to eat enough of these so that, over the course of a couple of weeks between May and early June, you can reach a weight of at least 180 grams.  If you do, you will have the fortitude to continue on to the Arctic and breed successfully.  Although, admittedly, you usually consume hard-shelled bivalves, your digestive tract has shrunk over the long migration leaving you unable to digest anything but soft, puny horseshoe crab eggs. If you don’t stuff yourself with enough of them, you’ve got nothing to keep you going. And this would be bad news for you, since you’ve burned through not only your fat reserves while in flight, but also a lot of your muscle and organ tissue.


The birds in this photo, taken at Mispillon Harbor, Delaware on 13 May 2007, represent a tiny fraction of the hundreds of thousands of birds that depend on the food resources provided by Delaware Bay. Several species of Arctic-breeding shorebirds are embedded in this group, including: Ruddy Turnstone, Red Knot, Semipalmated Sandpiper, Dunlin, and Short-billed Dowitcher. (Photo taken by Chris Bennett).

Two or three decades ago, you and your brethren – not just Red Knots but equally crab-egg-dependent Semipalmated Sandpipers, Ruddy Turnstones, and Sanderlings – arrived on the Delaware Bay in unbelievable numbers to partake of this delicacy. You flocked across the Bay shore of two states, filling airspace and obscuring sand to the amazement of birders on such beaches as Slaughter, Fowler, and Prime Hook in Delaware, and Higbee, Reeds, and Norbury’s Landing on the Cape May peninsula of New Jersey.

Cape May Bird Observatory Director Pete Dunne remembers first discovering this spectacle in 1977.  “The sound of the birds was a squeaky and chattering din,” he later wrote.  “The rattle of the crab shells in the surf recalled crockery in a well-stirred dishpan.”

This area is considered one of the four most important shorebird stop-overs in the entire world.  “I think of it as the mid-Atlantic Serengeti,” says Eric Stiles, New Jersey Audubon’s Vice President for Conservation and Stewardship.  The other three most crucial migratory shorebird stop-overs are Alaska’s Copper River Delta, the Wadden Sea in northwestern continental Europe, and the Yellow Sea, between eastern China and the Korean peninsula.

For a long time, no one thought the spectacle in the Delaware Bay would end.  Dr. Larry Niles, chief biologist with the Conserve Wildlife Foundation of New Jersey, says that, in the 1980s, estimated counts of the rufa Red Knot in Tierra del Fuego numbered about 90,000 individuals.   

Suddenly, in the mid- to late-90s, the numbers of Red Knots and other shorebirds appearing on the Bay for their mid-spring horseshoe crab egg gorge-fest fell dramatically.  By 1997, Red Knot numbers had shrunk by more than 50% to only 41,855.  The real low point came in 2003, when scientists counted a mere 16,255 Red Knots. The number has been fairly stable since then, fluctuating little from the dismal 2004 figure of just 13,315.  Meanwhile, the Semipalmated Sandpiper numbers in the Bay have plummeted by 80 percent.  But New Jersey Audubon’s Eric Stiles sees the Red Knot as the “flagship species,” the one that is “really emblematic for a whole suite of other species.”  In other words, the Red Knot is the “canary in the coal mine” for the conservation status of a whole range of shorebirds.

Horseshoe crabs, like these photographed at Slaughter Beach, Delaware 13 May 2007, have been crawling onto beaches along the Mid-Atlantic coast for millenia. They come ashore to spawn and in the process lay millions upon millions of eggs that are a critical food resource for northbound shorebirds that stop here to refuel on their way to Arctic breeding grounds. (Photo taken by Chris Bennett).

But what happened? While birders were ooo-ing and aah-ing over the annual spring shorebird entertainment, fishermen once again had their eye on the crabs.  Their take had been huge in the late 19th and early 20th centuries, when astronomical numbers of crabs were caught for the fertilizer industry, but shorebirds, severely persecuted by market and plume hunters, were few at the time.  These shorebirds, including the Red Knot, rebounded within several decades once they were spared the shotgun and horseshoe crab egg abundance spiked, to the point that the birds became the attraction that Pete Dunne had hailed 30 years ago.  During this period of recovery, fishermen had been catching a certain number of horseshoe crabs – especially “egg-laden” females – as bait for minnow and eel.  But, by the early 90s, they had learned of another lucrative use for crabs.  There was a newly growing conch industry, and crabs were perfect bait for conch.  So fishermen began carting away truckloads of the helmet-like animals as they came ashore to spawn; the catch increased from an estimated 100,000 crabs in the early 90s to two million later in the decade.


Horseshoe crabs are somewhat prehistoric looking when seen at close range. These crabs were photographed as they spawned at Mispillon Harbor, Delaware on 3 June 2008 (Photo taken by Jean Woods).

Fewer horseshoe crabs meant fewer eggs for the Red Knots and other birds, and they did not react well to this state of affairs.  By now, the problem was obvious.  A temporary moratorium on the harvest of horseshoe crabs declared by New Jersey Governor Christine Todd Whitman, and initially tentative harvest restrictions instituted by the Atlantic States Marine Fisheries Commission (ASMFC) – affecting not only New Jersey and Delaware, but other Atlantic coastal states like Maryland and Virginia – only saw the numbers of Red Knots and other birds continue to decline.  The hard fact is that horseshoe crabs take eight to 12 years to reach sexual maturity.  Mature and maturing crabs kept being permanently eliminated from circulation.

As a result, on the New Jersey side of Delaware Bay alone, the density of horseshoe crab egg distribution on the beaches remains poor.  In 1992, density was 50,000 eggs per square meter.  Eight years later, density had fallen to a minimal 4,181 eggs.  Two years ago, density was even lower, at 2,006 eggs per square meter.  

In 2004, leading scientists believed that, based on data, the rufa subspecies of the Red Knot would go extinct within six years.  And this prediction didn’t factor in the potential for a catastrophic oil spill in the Delaware Bay, which is a top U.S. oil transport waterway.  Dr. Niles warns that a major spill at the peak of migration could simply wipe out the Red Knot.  The birds have enough natural threats now, at a time when their population is “essentially skimming bottom,” as Dr. Niles puts it, without the additional problem of deadly oil slicks.  

In New Jersey, a statutory moratorium on horseshoe crab harvesting will remain in effect until various goals are reached.  Delaware has yet to enact similar legislation, and a rule imposing a moratorium was overturned in court, but crab fishermen are limited to the maximum harvest of 100,000 set by the ASMFC.  The state has taken further initiative by limiting this harvest to males. 

The fact that any harvest at all is permitted in the face of the likely extinction of the Red Knot motivated Bill Stewart, the Conservation Chair of the Delmarva Ornithological Society (DOS), to take action.  He declares, “If it wasn’t for Delaware, I don’t think that the Red Knot would exist.”

In 2007, he decided to organize a DOS Bird-A-Thon to raise funds for the purchase of Bay shoreline in Delaware then in private hands.  Partnering with the Conservation Fund, the DOS agreed to provide $15,000 the first year and, thereafter, donate what turned out to be increasingly more impressive totals, so that the Fund could buy shoreline and turn it over to Prime Hook National Wildlife Refuge for “eternal management.”  There, no crab harvesting would take place. So far, the DOS Bird-A-Thon has helped the Conservation Fund purchase 16 acres of shoreline.  The Fund is now working on buying 64 more acres (two miles), and a special DOS account has $28,000 in reserve for this purpose, while Stewart expects to raise another $35,000 this year toward that end.  (Additional monies support the Ashland Hawk Watch in northern Delaware.)


With funds raised through their annual bird-a-thon, the Delmarva Ornithological Society hopes that important feeding sites, like this one at Mispillon Harbor, Delaware, can be purchased and turned over to Prime Hook National Wildlife Refuge. Once a part of the refuge system, such beaches would be off limits to those who harvest horseshoe crabs and would also provide a safe haven for the shorebirds that come to feed on crab eggs. (Photo taken by Jean Woods). 

Last year (2008), the Bird-A-Thon attracted 433 participants of all skill levels who collected pledges based on the number of bird species they saw or heard in Delaware in a 24-hour-period during any one of several days in May. Stewart notes that this fundraiser has enjoyed considerable support from people all over the U.S. who send in checks earmarked for the Bird-A-Thon.  This year, the dates for the DOS Bird-A-Thon are May 2-10.  People can learn how to participate or simply donate by going to

Ultimately, Dr. Niles, Eric Stiles, and other conservationists believe that only a complete moratorium all along the Atlantic coast on horseshoe crab harvesting will allow the rufa subspecies of the Red Rnot to recover.  Maryland and Virginia permit harvests off the coast in accordance with ASMFC quotas:  Virginia allows 70,000 crabs, which is less than its quota, while Maryland has chosen to harvest its quota of 173,000, but at a rate of two male crabs for every one female.  The significant harvests in Maryland and Virginia remove crabs that would have eventually ended up in the Delaware Bay to spawn.

Under former President George W. Bush, work under the Endangered Species Act came to a virtual halt.  The U.S. Fish and Wildlife Service has restarted efforts on endangered species under President Barack Obama, and the rufa Red Knot was recently elevated in priority for consideration as endangered.  Nevertheless, Dr. Niles urges that we can’t wait for the federal bureaucracy to afford protection to the rufa.  Today’s annual crab harvest levels of 400,000 are substantially greater than the estimated harvest prior to the Red Knot’s decline.  “Once the crab population gets back to its carrying capacity, where it was before it was over-harvested, then we can harvest crabs and we will have enough crabs to make eggs for shorebirds,” Dr. Niles observes. “We need to get back to that as soon as possible. We’re slowing recovery down because we’re still harvesting 400,000 crabs.”

Acknowledgments and Literature Cited:

In researching this article, the author spoke with Kevin Kalasz, Wildlife Biologist, Delaware Division of Fish and Wildlife; Stewart Michels, Fisheries Scientist, Delaware Division of Fish and Wildlife; Dr. Larry Niles, Chief Biologist, Conserve Wildlife Foundation of New Jersey; Bill Stewart, Conservation Chair, Delmarva Ornithological Society; Eric Stiles, New Jersey Audubon Vice President for Conservation and Stewardship; and Dr. Jean Woods, Curator of Birds, Delaware Museum of Natural History. 

The author also relied on the following articles:  “Effects of Horseshoe Crab Harvest in Delaware Bay on Red Knots:  Are Harvest Restrictions Working?”, Bioscience Magazine, February 2009, by Dr. Larry Niles, Kevin Kalasz, and 18 others; “Horseshoe Crab Spawning Activity in Delaware Bay:  1999-2008,” Report to the Atlantic States Marine Fisheries Commission’s Horseshoe Crab Technical Committee, February 9, 2009, by Stewart Michels (Delaware Division of Fish and Wildlife), David Smith (U.S. Geological Survey), and Sherry Bennett (New Jersey Division of Fish, Game and Wildlife); and “How the Knot Became Undone,” New Jersey Audubon, Spring/Summer 2007, by Pete Dunne.


A fabulous set-up and examination by Dr. Rosenthal, and a new high-water mark on BirdFellow in my opinion. The rufa Red Knot forages in money, while the Marbled Murrelet, which I teach people to recognize and survey for, made the terrible decision to actually nest in the filthy gray-green substrate. As I am writing this, Irons just called—and we agree that it doesn’t matter if you’re sipping coffee beneath a different flyway and haven’t seen the Delaware Bay—the problems faced by the birds are just as real. I would only add that shorebirds, as well as murrelets, are not a “natural resource.” They are separate nations of beings. Unless we get as many people as possible bird-conscious, what we cherish will disappear. Make the choice to speak and vote for those who cannot.


My sincerest gratitude goes out to both Dave and Elizabeth in showing such incredible support for our Bird-A-Thon efforts and revealing to others the significant plight facing many migrating shorebirds. All birders, conservationists, ecologists and others have their own “red knot” dilemma confronting them within their own backyard or region. Now more than ever, we need to take action to create change for our avian friends, whether it be through citizen-science efforts, education, proactive measures or the other multitude of opportunities available to all who look and listen. Simply ask yourself if you are an observer of nature or a participant with nature. Once you answer that question and discover you want to participate with nature, many doors will open for you and your experience will become much wider and richer.
Again, thank you for your support and providing Elizabeth the opportunity to share her wonderful writing style and skills.

Good birding.


Soft shells can be great, but snayig that king or Alaskan crab legs are anywhere in the same range as delicious as blue crabs is just plain insane. They taste more like imitation sushi crab than actual delicious, silky, rich blue crab meat. And yes, picking crabs is a ton of work. Your hands get cut up, the old bay stings, you spend a lot of time to get a little bit of meat. But that’s the entire point! Earning your dinner, getting messy with your loved ones, and throwing back some cheap beer are all part of the delightful, rewarding, beloved process of picking crabs. It is my favorite thing to do with clothes on. Yes, I grew up in the mid Atlantic. It’s tradition, and one I’m incredibly happy to have. It’s a shame you don’t enjoy it, but that’s ok. More crabs for me.Oh, and also, a proper crab feast is not a crab bake. You steam crabs. You bake clams.


Soft shells can be great, but snayig that king or Alaskan crab legs are anywhere in the same range as delicious as blue crabs is just plain insane. They taste more like imitation sushi crab than actual delicious, silky, rich blue crab meat. And yes, picking crabs is a ton of work. Your hands get cut up, the old bay stings, you spend a lot of time to get a little bit of meat. But that’s the entire point! Earning your dinner, getting messy with your loved ones, and throwing back some cheap beer are all part of the delightful, rewarding, beloved process of picking crabs. It is my favorite thing to do with clothes on. Yes, I grew up in the mid Atlantic. It’s tradition, and one I’m incredibly happy to have. It’s a shame you don’t enjoy it, but that’s ok. More crabs for me.Oh, and also, a proper crab feast is not a crab bake. You steam crabs. You bake clams.


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