Crash: A Tale of Two Species
Why save the red knot?

Red knots in flight

Among flocks of shorebirds, the red knot is fairly average looking. In fact, only the most practiced bird watchers may be able to distinguish this medium-sized, plump peep from the thousands of other shorebirds playing tag with the waves. Yet, somehow the red knot has caught the attention of people around the world.

The knot’s dependence on the eggs of the heavily harvested horseshoe crab has placed it at odds with another species — humans. Conservation groups, lawmakers, fishermen, scientists, and ordinary citizens have all entered the debate. But even as our actions have imperiled the red knot, we can also preserve the species, by regulating the fishing industry and keeping clear of the beaches that the knots rely on during migration. Where nature ranks in our system of values will dictate how far we are willing to go to protect the red knot.

There are millions of shorebirds in the world. Why all the clamor over the red knot? How could this small bird stir up so much controversy and inspire such extraordinary efforts on its behalf? To begin to answer these difficult questions we must first become familiar with the red knot.

The red knot may blend in with the other small shorebirds, but it makes a journey that certainly sets it apart. A master of long-distance aviation, the red knot makes one of the longest migratory trips of any bird — 9,300 miles along the Atlantic flyway from its wintering grounds in southern South America to its high Arctic breeding grounds. The journey is so exhausting, it requires two to three stopovers for refueling. The horseshoe crab egg feast they will consume at Delaware Bay, is not just an indulgence — it’s absolutely crucial for the birds’ survival. When the knots arrive at Delaware Bay, their bodies are half their starting weight, devoid of fat and even some muscle. Here, the red knot will take about two weeks to double its weight so it can continue its migration.

The migratory trip is far from the only risk the peeps take in their lives. The life of the red knot is fraught with challenges. In their wintering grounds of Tierra del Fuego, blinding gales blow up without warning, and tides surge 25 and 35 feet every 12 hours. The challenges facing the knots are even greater on the Arctic nesting grounds, where a declining population of birds makes it more difficult to find a mate and even if they do, a snowstorm can wipe out the knots’ eggs. If the birds don’t consume enough eggs during their migratory stopover, they may not have enough fuel to complete their trip, and those undernourished knots that do make it to the Arctic will arrive weak and emaciated. Add the fierce and unpredictable Arctic weather into the mix, and the birds are likely to be in such a state that it is nearly impossible for them to raise chicks.

researchers tag red knot shorebirds 

Researchers tag red knots in Crash: A Tale of Two Species.

Nature, it seems, has really stacked the deck against this creature. During its migration, the red knot concentrates in huge, densely-packed flocks. These enormous gatherings make the knots vulnerable to habitat destruction and, in South America, hunting pressure. Sadly, it is not just their eating preferences but their social patterns that put them at odds with human activities.

All of these hardships have given rise to dire statistics. The red knot is a creature in peril. The U.S. Shorebird Conservation Plan lists the red knot as a “Species of High Concern,” based on declining population trends and threats on non-breeding grounds. In the last 20 years red knots have declined from over 100,000 to less than 15,000. And in 2006, the knot was named a candidate for Endangered Species Act protection as an emergency measure to slow the rapid fall of its population. In the Delaware Bay, the knot has suffered a decline so severe that some experts predict the population stopping over at the bay could disappear within five years.

Studies conducted outside of the U.S. do not paint a brighter picture. Counts of knot populations wintering in South America dropped over 50% from the mid-1980s to 2003. Researchers have suggested that the continued hunting of knots in South America might be partly to blame.

The red knot is one of the world’s most amazing birds. But if that is not sufficient motivation for us to save it, there are other incentives. Chincoteague, Virginia, a popular stop-over for the red knot, finds that what is good for migratory shorebirds is also good for Virginia business. A recent tourism survey found that birders and ecotourists were bringing in significant amounts of resources to the local economy. And one economic study in South Jersey found that the shorebird-watching industry generated nearly $36 million dollars in revenue for the area.

Sadly, the issue raised in Crash: A Tale of Two Species over the increased harvest of horseshoe crabs remains contentious today. Whether the red knot will be able to continue to use Delaware Bay as a major migratory staging area in the future is still up in the air — as is the fate of the knot.

For more information on red knot conservation efforts, visit, where Larry Niles (featured in Crash: A Tale of Two Species) and an international team of scientists blog about the most recent news on the red knot.

  • nancy

    Great program. I love the horsehoe crab!! Can we get an update? Have we saved the red knot? Has the horseshoe crab population increased as a result of the NJ legislation?

  • mark

    research shows that they were getting plenty of food from the delaware bay to make their journey….Do you think it might be the HUNTING in South America that they are having trouble surviving ?????….

  • Alexandra

    This little bird, the red knot, is amazing! And I believe that this bird will succeed its journey, but it has a long way to go.

  • Harry Pauley

    When hundreds of birds take off at the same time, why don’t they run into each other?

  • John

    Enjoyed the program. Would be interested in updates on the birds and crabs over time. The program didn’t mention hunting, or I didn’t catch that reference. All life seems intertwined, except we humans have found a way to exempt ourselves from the natural web. Probably not a good thing for the earth and eventually, not good for humans either.

  • Mark Cortright

    Great program -what”s the update on each species???

  • Dave Johnson

    What a great show! Incase some have missed the importance of the Red Knot, if not for this little bird, scientist may have never been aware of the overfishing of the horseshoe crab along the alantic coastline. As this show has shown, without the blood of these crabs, many of our modern day medicines would never have come to light which possible save the lives of our love ones and ourselves. Besides their intrinsic value to nature we humans need to cherish all creatures big and small. Maybe one day one may unlock the secret to curing diseases like cancers…if we’re not so selfish to allow them to wither away.

  • Joseph Timm

    It goes to show just how fragile “our” nature system is. We must be better caretakers or we may be next.

  • Frank Humphreys

    Thoroughly enjoyed show and have watched it over many times, each time picking up something I missed. We need more shows like this, my thanks go out to all the volunteers involved in this and all other endeavors they pursue. I pray that the Red Knots, Horshoe Crabs and all species can survive. THANKS

  • phyliss

    I truly enjoyed the show. The Red Knots are such amazing little birds taking a long journey to get to their destination. I never knew horseshoe crabs have blood let alone blue, that is fantastic. The program was beautiful.

  • Bonnie

    An exceptional program. More research / data and reporting on the effect of hunting would be useful. Why is it not banned? Also: info on whether research is underway to replace the natural horseshoe crab blood with a synthetic; whether crab eggs can be hatched in preserves to ensure a higher survival rate; whether crabs depleted of their blood survive once returned to the water (and how you determine the survival rate). The capture, blood-letting, and release of the crabs was medieval … truly inhumane and horrifying. The pricing of a quart of crab blood at $15,000 equally so … Who are these pirates? Naming names would be helpful.

  • loviell

    save nature same as u save earth,and saving ourselves…..the day is beautiful when watching them flying free….

  • Shonda

    What a wonderful way to call attention to the plight of the little things in life that people take for granted. Just found a web site “Friends of the Red Knot”. They have letters that can be downloaded and sent to Secretary Salazaar and Governor O’Malley. I think everyone impacted by this fantastic show should start writing letters to get policy in place to protect these species, and other species from extinction. If everyone just took a few minutes, to sign these letters and drop them in the mail, it will make a difference. Thanks to the children who started Friends of the Red Knot!

  • rainy

    profits, its all about greed and more profits. people actually think those business man will even care about this? we need more harsh regulations.

  • jlo

    hay hte red knot is pretty amazing so letts keep it that way instead of saying the red knot was amazing

  • caily

    lets save the red knot we’ll do what ever it takes!!!

  • Tony McGuane

    i think they should save the red knot. they are an endangered species and they should be saved. i think this was a pretty interesting article.

  • michaelpDHS

    i think this little bird should be given more attention. if they go extinct then some small towns economy will plummit and will cause a chain reaction in the ecosystem.



  • Cynthiaaa

    I agree with Gelviz !
    theres no reason for this species to become extinctttt,

  • Larry Carter Center

    We need to invest in more observers and protection/enforcement across the globe. We can end the war on the environment, war on habitat, war on our own species. If people could just choose science and sustainable careers, be involved democratically instead of allowing corporations fascist power over our lives. We can restore our garden earth. This beautiful bird flies pole to pole and more of us could sail our oceans with wind power and love all life. Larry Carter Center

  • Lynn K Stimeling

    I’m unable to locate any links to the 2009 shorebird census figures. The 2009 horseshoe crab census is disappointing. Does anyone have access to the 2009 red knot count?

  • kat

    I love this bird, they’re adorable and I don’t want them to go extinct at all. I admire their strength and determination. But I was wondering-do they give anything back to the environment? Why are we striving to save the Red Knot besides the fact they are amazing creatures?

  • nick

    I agree with kat (except for the admiring part) on top of that I think evolution failed with them in that why would you go around the world just to mate?

  • Mike

    I’m pretty naive about this, however are mentions of hunting this small bird serious? Do we hunt Robins (similar in size)?

  • Srividya

    Amazing program. Its disgusting to know Man would almost interfere in any part of eco system and make things worse for animals and birds…. If only our greed to consume animals stopped! I really hope red knots and horse shoe crabs are saved.

  • Bo

    All creatures have a place on this planet even if we may not know its purpose. Evolution has not failed the Red Knot and put the Horseshoe crab in danger. We humans have mostly done so. I realize that we rely on the ocean and land to provide food for the world. However we are using up our planets resourses to provide for an overly populated world of humans. Only humans can take a proactive role in controling the over population and the problems that come with it. Each person should only reproduce one child. This simply replaces one with one. It’s a good place to start and take it world wide.
    It is easy to watch a show like this and hear the message of conservation and be concerned. I challenge you to practice that message for the rest of your life. You don’t have to change the whole world by yourself, do what you can and invite friends to go with you.

  • Thoughtful

    Evolution does not “fail” a species. Evolution is just a term that we use to describe a process that happens in nature. It just so happens that the recent actions of human has interfered with the lives of Red Knots much more than with the lives of many other organisms and we are thus driving them to extinction. Therefore, what we must consider as humans is how much we value nature. Once we have determined that, we will know what choices we ought to make on this topic of conservation. One extreme position is that we could say, “I don’t care at all about conservation of nature,” and we could proceed to do whatever it is that we like without stopping to think what effects our actions will have on the other species that occupy this Earth. The other extreme position is that we could say, “As a human, I do not want to limit the habitats or niches of any species on Earth, and thus I will aim to limit human presence on Earth as much as possible so that we will not diminish the number of individuals in any species.” I think it’s safe to say that the vast majority of humans fall between these two extremes in their position on conservation of nature.

    I personally wouldn’t mind denying humans the right to fish at will (i.e. I wouldn’t mind putting regulations on their fishing) if their fishing was causing species to go extinct. In the case of the Red Knot, it seems to me that us humans have suddenly started hunting horseshoe crabs much more abundantly in recent years. Assuming that this action is having a great effect on the number of horseshoe crabs and thus also the survival of other species (e.g. Red Knots), then I think that we ought to put regulations on fishing for horseshoe crabs so that we do not suddenly change what has been happening in nature for millions of years, thus driving species to extinction.

    For another personal opinion, I will say that I recently became very conservative politically because I didn’t like the idea that one human ought to be allowed to create a law to force another human to do something against their will or not be allowed to do something that they want to do. Should an individual be allowed to fish whenever he or she wants? Perhaps I thought so before, but after realizing that an individuals’ actions affect the world (greatly when great numbers of individuals are performing the action (as with horseshoe crabs and Red Knots)) I have now come to realize that there is a certain degree of freedom that we ought to allow the individual and this degree of freedom depends on the degree of which the individual’s actions are affecting the environment and the world. I’m becoming liberal again. We will not be able to prevent the extinction of many species, not just Red Knots, in the future, unless we are willing to give up our rights and are willing to take the rights of others away.

  • Peter D

    We depend on nature and animals to survive. Pollution, eating species into extinction and massacre of environment happens on global scale:
    sacred and very needed by life on Earth trees are being massacred by human predator. Gold mining, illegal tree cutting,
    illegal ranching in Amazon already destroyed a lot of sacred trees. Animals’ habitat is disappearing with exponential (unbounded) rate. Films: “AMAZON with Bruce Perry”,
    “The End of the Line (2009)”. Most vicious predator (human) must learn to stop destroying its own environment. (Aside: the human is most vicious
    predator because it kills for sports.) While most vicious predator propagates with exponential (unbounded) rate, the nature and animals disappear with exponential
    rate at the hand of most vicious predator. Most vicious predator must stop unbounded (exponential) reproduction: it leaves no space for healthy environment
    for most vicious predator and leaves no space for animals. CONSUMPTION is not “cool” anymore. Echo-systems sustain the economies. Economies do not sustain the echo-systems.
    Bottom-lines and corporations only destroy the nature, environment and animals. In the past, we hoped that our
    technology would help us to live better lives, but as of today, our technology (better traps, binoculars, nets, better sonars to track our prey, better guns, etc) only leads us to the SIXTH EXTINCTION
    of all life on the planet, at the hand of the human. If you cannot farm it – do not kill it.

  • Robin R.

    I think it’s sad that people go on harvesting horseshoe crabs now that it’s been made aware that the red knot is solely dependant on them ( horseshoe crabs) for its survival. With the decliining rate of these little birds, it really breaks my heart that so many humans, who obviously play a major part in the extinction of wild animals, still don’t seem to care enough to prevent it!

  • Patricia Goodwin

    After watching your Crash: A Tale of Two Species I will most certainly watch for the Red Knots this year. I will show this doctumentary to my 12 grandchildren so that they may help to restore these two species. I have noticed the decline in the HorseShoe Craps in the North Cape area. I knew they were being used in medical research, but didn’t know that most were returned to their habitat. Keep up the wonderful work you do to save the endangered animals throughout this planet. Thank You!!!

  • Tom

    I came here hoping they would explain why we should save the red knot, but other than for the sake of doing so or for our own selfish purposes in exploiting them for money, I don’t think they gave much of an answer. I am all for helping to preserve a wildlife species that we are directly causing peril, I was just hoping for a stronger point to be made, given the article name.
    I find it interesting that in an effort to increase the birds’ food supply (because they apparently don’t care to save the horseshoe crab otherwise), the state is essentially taking away the food supply of those watermen who rely on the crabs as bait. I am glad that a synthetic bait is being worked on, but it saddens me that families have to suffer in the meantime. I can imagine their frustration. I liked how the show made their plight mirror that of the red knots in that it shows that if your lifestyle is so delicate and rigid that you cannot adapt, your path is a difficult one. I was amazed to learn about the red knot’s long time-sensitive travels through harsh environments, infrequent stops and ability to find an adequate food supply, but those same characteristics that make them so remarkable may cause their extinction if they cannot change.

  • Justin

    I came here to see why we should save the Red Knots. They dont seem to contribute anything to humans so why are we devoting so much money energy and time to them when that could be going to the horseshoe crabs who actually seem to be helping humans? Yeah it sounds selfish but these birds dont help anything but diminish the horseshoe crab population by eating the eggs. The Red Knots have an amazing journey and endure hardships greater than most but that is their own fault which will lead them to extinction like thousands of animals before them. Some animals just are not made to make it for long on this planet. Now the Horseshoe Crab needs more attention. Their population was diminished by humans and we can change that and use these creatures to help us out just like we are helping them. If we save these birds what will they do for us? Nothing but help get rid of a species that helps us. Sounds bad but its reality.

  • iHateRedKnots

    We must eradicate the vile Red Knots.

    At no point has anyone shown any positive effect that the Red Knot has on any other part of the environment (besides “Virginia business”). Yet their foolish worldwide migration has a distinct impact on the noble Horseshoe Crab.

    Yes, the bird is cute and fuzzy, and the crabs are weird nightmare-fuel. However, the crabs are useful not only as commercial bait, but much more importantly as resources for medical testing and the development of drugs.

    What eats this stupid bird? I went to this website after seeing the link during the show, hoping there would be some clarification as to how these birds were integral to a larger ecosystem, but it seems the primary reason to save them is that they are “amazing”.

    It is clear that the Horseshoe Crab is an extremely useful animal and is hardy enough to survive relatively unchanged for millions of years. On the other hand, this fool’s bird travels halfway around the globe every year for no discernible reason, just so it can eat crab along the way. I hate this bird.

    When I saw the researchers out on the shore counting and worrying about these birds through their binoculars, I couldn’t help but think that they should have had rifles.

  • Joseph Seigle

    Thanks so much for sharing this! I wish natural food coloring would be as common as the chemical stuff.

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    I have had mine for about a month and just love it. I now have 4 and will never go back. Thank You Karim

  • Melba Steinhart

    I really enjoyed your page, the content was brilliant, hoping for more great updates in the future

  • astma

    Od dawna szukałem artykułu na temat Crash: A Tale of Two Species – Why Save the Red Knot? | Nature | PBS . Dzięki

  • Lilly

    how much do they weigh when they arrive at Delaware bay?

  • superiorhumanbeing

    The comments that red knots are useless birds and cannot adapt to eating other food therefore deserve extinction remind me of early human society’s arguments that native tribal people were occupying land that the settlers wanted and they were inferior to the western culture, therefore they should be eradicated. From an ecological perspective, a healthy and functioning ecosystem requires all its living organisms. This article did not address how red knots being part of a larger web of life does not mean that they are isolated in the ecosystem and if taken out would not impact the balance of a larger world. Just like people did not know how red knots rely on horseshoe crabs for their refueling, we could just not know how other animals or ecosystem functions rely on red knots.

    What’s more important is that this earth is not just created for human’s consumption. If you believe in God and God created the earth and humans, God also places humans as the guardian of the earth and its living beings. Should we allow the destruction of God’s creations?

    For the arguments that fishermen would use horseshoe crabs as baits will suffer if they are not allowed to use as many horseshoe crabs as they wish, first of all, using horseshoe crabs as baits is only a recent phenomenon. For hundreds of years fishermen did not need to use them. Secondly, talking about the superiority of human beings, we are smarter and more adaptable to changes than both the red knots and horseshoe crabs. We can invent things that solve the problem without destroying others.

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