Larry Niles’s working life has been spent conserving wildlife as a biologist for government agencies, academic institutions and non profit conservation groups. His career began as a regional game biologist in Georgia where he led projects on white tailed deer population management and studies of black bears in the Okeefenochee Swamp. In 1982 Niles joined the NJ Endangered Species Program. Over the next 25 years he spearheaded research and management projects on shorebirds, colonial water birds, migrate songbirds and raptors and directed work on many other bird, reptile and invertebrate species. He is featured in Nature’s Crash: A Tale of Two Species.

How are current red knot populations doing?

Well, I believe we did the film in 2008. In both 2009 and 2010 the population remained stable in Bahia Lomas, that’s the main wintering area for red knots and in a few other wintering areas in South America. In the U.S. the numbers more or less remained stable. So we were hopeful that it had bottomed out. With species like this it takes a long time to recover because they are a low-productivity species, so once they get down to a certain level it takes decades for the population to get back to where it was. We knew that the recovery would be slow.

But this year, 2011, in Tierra del Fuego the number of birds went from 16,000 down to 11,000. They had a similar decline in an aerial count done two weeks earlier in the exact same area. Two surveys verify that there were less birds in Bahia Lomas. The Aircraft survey went down to Argentina in Rio Grande and found 400 in a place where there were 800 last year. In the year 2000, we counted 56,000 red knots in these two places. And now, based on the aerial count, we have less than 10,000. And what’s even more alarming is we had at least a 5,000 bird decrease in one year. We don’t know exactly what that means yet. It’s bad for sure.

The first question is, Did the birds move somewhere else? We covered all of Tierra del Fuego but we didn’t cover the area north of the Strait of Magellan because those places had blanked out years ago. We didn’t see the need to survey them. Next year we will expand the area of our survey. But another way for us to check this to see if it was an actual decline in numbers or if the birds have just moved around is back in Delaware Bay. The counts in Delaware Bay trend the same. We’re going to wait and see what happens in Delaware Bay.

We saw a lot of juveniles in the flock, and that’s a good thing. It means that birds left Delaware Bay in good condition, got to the Arctic, and the Arctic was reasonably hospitable for breeding. But it’s alarming because, in normal years we don’t have many juveniles. So if you were compare the numbers from this year to last year and just looking at adult red knots, the drop would’ve been much more. The count this year was inflated a bit by the production of juveniles.

So this is a very uncertain situation. If you have a loss of 5,000 birds when a population is 100,000 then it’s significant but it’s not going to determine the fate of the population. But when you have 16,000 and you lose 5,000 then that’s a very significant thing. It’s not likely that this decline is related to Delaware Bay because it’s so dramatic. But the collapse of Delaware Bay brought the population down to this low level. Now natural forces could wipe it out.

So the collapse of Delaware Bay might have started off this trend of decline but now there are other factors at play that are affecting populations?

Yes, we think that the main affect of the collapse of Delaware Bay as a stopover was the poor production of juveniles. Ideally, birds leave Delaware Bay for the Arctic, breed and produce a crop of juveniles. But because birds were leaving Delaware Bay in poor condition due to the lack of crab eggs, they reached the Arctic and either didn’t breed or bred unsuccessfully. So as adults died they weren’t being replaced by juveniles and the population went down.

The other impact of Delaware Bay is that if birds leave Delaware Bay in poor condition and hit bad conditions on the way to the Arctic or in the Arctic the adults may die before getting a chance to breed. If Delaware Bay was doing what it should be those birds would have lots of fat and they could live off that fat until conditions improve. But if they don’t have that fat, it’s like being in the Arctic without a winter coat.

When you bring a population of animals down to a low level, you still have all the other natural influences. One of the natural influences would be the hurricanes and tropical storms coming through the Atlantic and Caribbean when the birds are going south. These may be increasing because of climate change, but they’ve always been a problem. A red knot might spend up to 4-5 days over ocean before it hits land. If it encounters a storm and is blown off course it may not make it. Say this happens and 5,000 birds are killed in a season. If there are 100,000 birds, that’s 5 percent of the population. But if you have a lower number, 25,000 birds, now it’s 20 percent of the population. If it’s 15,000, then that’s a third.

And you mentioned climate change causing more harsh weather conditions. Has climate change also affected the Arctic breeding grounds in an adverse way for the red knots?

It’s hard to say what’s happening in the Arctic. Our group of knots breed mostly in the Archipeligo islands in Canada just above the Arctic circle. The habitat is of a higher elevation and barer because of that. It’s around 75 percent snow-covered. There’s a reason for that because they’re trying to nest in areas that have a very low predation rate. If climate change generally warms things, then I don’t know what their new strategy would be. Would they go to a higher altitude? Would they go to more northern islands? We don’t know enough about the effect of climate change in breeding areas.

But in temperate and tropic areas I think it can have a significant impact. We tracked a bird last year with a geo-locator, a device that stores information, that encountered a tropical storm on its way south and flew over 1,000 miles off course out to sea. It was lucky enough to make it back and successfully land in the northern coast of Brazil. But birds are physiology planning on a flight to Brazil. They aren’t planning on a 1000 mile detour.

Have the horseshoe crabs had a similar decline recently?

The major decline took place during the 90s and the early 2000s. Then they bottomed out in 2003. But in the last few years, the surveys have been in conflict. Some surveys suggest there have been an increase in the number of eggs on the beach, some are showing no increase. There has been an increase in the number of juveniles. I think it has gotten better but I don’t think there is significant statistical basis for that.

Another way of looking at it, when we make our catches of shorebirds each year we compare the percent of birds that make 180 grams because 180 grams is more or less the threshold weight that we estimate birds need to successfully breed in the Arctic. Back in 1998, 80 percent of the birds that we caught at the end of the season were over 180 grams. In the worst of it we were getting 5 percent of birds making it to 180 grams. Last year it was 40 percent. So that’s an improvement. But it’s an improvement with a population that’s a quarter of the size that it once was. So naturally you need less eggs because you have fewer birds.

What can people do in order to stabilize and improve the populations at red knots?

Well, I think there’s two things. First, we should really not be harvesting crabs until there’s clear signs of improvement. There are still 400,00 crabs killed each year for bait. One thing people could do is keep the pressure on their legislatures, especially the people in New Jersey, Pennsylvania, Delaware, Maryland and Virginia.

The second thing is that people need to become more aware of the situation of shore birds. We’re talking about the red knot but we now have evidence that sandpipers and even common species like lesser yellowlegs have declined by 80-90 percent in the last 20 years. So what we are looking at with red knots is a serious decline but all the arctic nesting shore birds are in trouble.

In the 1930s, when water fowl were in trouble, the sportsmen started programs, duck stamps, paying taxes on their guns and ammunition — they did things that ultimately led to the restoration of water fowl populations. I would say, people who like birds need to start doing something. It’s not just governments or conservation groups. If the hunters had left it up to governments and groups then we probably wouldn’t have any water fowl species right now. But they didn’t. They took control. And I think now is the time for people who like birds to start doing something, start demanding that they tax binoculars and put that money into programs, or demand that there is a shore bird stamp and the money raised would go toward restoration programs. I think there is need for serious action now.

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For many decades, humans have harvested the horseshoe crab for use as fishing bait. Since the 1970s, we have also used horseshoe crab blood for medical purposes. But we may have gone too far. Horseshoe crab numbers have declined significantly since the early 1990’s. And, naturally, so did their egg numbers.

This is especially important to a small shorebird that is a global traveler of the most impressive kind. The red knot makes one of the longest migrations of any animal — a journey that takes it from one end of the earth to the other. To accomplish this feat, it relies on the eggs of the horseshoe crab. Without these eggs, the red knot is in danger.

In the film Crash: A Tale of Two Species, filmmaker Allison Argo tells the story of nature’s amazing ability to create fragile connections among the most unexpected creatures, and of our potential as humans to destroy those connections — or restore them.

To order a copy of Crash: A Tale of Two Species, visit the NATURE Shop.

Online content for Crash: A Tale of Two Species was originally posted February 2008.

This is the story of the fabric of life, and how every species is interconnected – each one important, no matter how big or small.  At its center is the humble horseshoe crab, a creature which has remained virtually unchanged for 350 million years.  Its annual spring spawning produces millions of eggs that are the lifeline for a tiny bird called the red knot, which migrates 10,000 miles from South America to the Arctic each year. Scientific and medical communities have discovered that the crab also provides an indispensable testing agent for drugs and vaccines, as well as resources for human optics and burn treatment.  But horseshoe crab numbers are plummeting from their new use as bait for the fishing industry, dropping by two-thirds or more since 1990.  And the precious pyramid depending on this age-old creature is about to come crashing down. Filmed and presented on television in high definition. Buy the DVD. This film premiered February 2008.

It may sound strange, but the U.S. State of the Birds press release filled me with a sense of relief.  The report, released on March 20 by Secretary of the Interior Ken Salazar, reveals that one-third of our nation’s birds are endangered, threatened or in serious decline.  This “breaking news” is something many of us have known for years – but it went unreported by the prior administration.  Now, at last, the word is out.

The fact is, birds face a very grim reality and there is no time to waste.  We must do everything we can to turn the situation around – and that means ALL of us. Find some ideas for getting involved at the State of the Birds Web site.

My recent film for NATURE, Crash: A Tale of Two Species, told the story of a small bird called the “red knot.”  No bigger than a robin, the red knot makes one of the longest migrations on earth – from the tip of South America to the Arctic(!).  But today these migratory marvels are hanging on by their little toenails… and it’s all because of human activities.

Watch my behind-the-scenes video about the making of Crash: A Tale of Two Species.

The exciting part of the State of the Birds report is that it offers hope.  It reports that where efforts have been made, there have been tangible improvements.

This is why I make films.  To bring these life-altering issues to the public – and in doing so, to bring a bit of hope.  Only if we’re aware of the problems will we be able to fix them.

My latest film, Frogs: The Thin Green Line, delivers no less urgent news than the bird report.  Up to one-half of the world’s amphibian species are threatened with extinction.  It’s being called the greatest mass extinction since the dinosaurs.  It is HUGE… but there is much that the average citizen can do to stem the tide.  As always, the first step is awareness – and that’s where NATURE comes in.

Yup, this is why I make films.  I hope you’ll tune in!

Frogs: The Thin Green Line is scheduled to premiere on NATURE on Sunday, April 5, on PBS (check local listings).

Crash: A Tale of Two Species is scheduled to air on NATURE on Sunday, April 26, on PBS (check local listings). Watch it online now.

The horseshoe crab is at the center of a contentious debate, and one that plays the world over. How do we find the balance between man and nature?

In the Delaware Bay, the clash over horseshoe crabs has embroiled experts, agencies and people in a heated debate that pits the survival of the red knot against the livelihood of fisherman and the U.S. pharmaceutical industry.

And, in order to find a solution, The Audubon Society, the Atlantic States Marine Fisheries Commission, the New Jersey Department of Environmental Protection, the U.S. Fish and Wildlife Service, conservationists and long-time bay watermen are all looking for one thing, an answer to how many horseshoe crabs there are – and how many there need to be to maintain the ecological balance of the bay if the red knot is to have any hope of survival.

Little is known about the status of the horseshoe crab population. Because their population has only been studied recently, there is limited data which makes it difficult to assess its status. What is known is that prior to 1998, millions of horseshoe crabs were taken from the Delaware Bay in an unregulated fishery. But now, attention is being paid.

Based on recent survey data, the Delaware Bay population appears stable. Dr. Dave R. Smith, Aquatic Ecology Lab, USGS believes evidence from recent assessments and monitoring data indicate that the horseshoe crab population in the Delaware Bay region is experiencing positive population growth. Recent surveys have shown significant increases in the numbers of juveniles and adult horseshoe crabs. These encouraging signs provide hope for the horseshoe crab and shorebird connection in Delaware Bay.

Dr. Smith believes these gains are most probably in response to direct action taken by the fisheries commission because of declining migratory shorebird populations. In 2000, the Atlantic States Marine Fisheries Commission (ASMFC) established state-by-state quotas in all Atlantic states for crabs harvested for bait, limiting the number of horseshoe crabs that could be harvested. And, in 2006, the ASMFC further reduced the number of horseshoe crabs that could be caught in Delaware and New Jersey to 150,000 per year and added additional protection in Maryland and Virginia to increase horseshoe crab abundance in and around the Delaware Bay.

Another crucial step was the establishment of a no-harvest zone (the Carl Shuster Reserve) in the ocean off the mouth of the Delaware Bay. The aim of the no-harvest zone is to protect older juvenile and newly mature female horseshoe crabs from being harvested, allowing them to reach sexual maturity and begin reproducing. Dr. Smith believes that the current management program, which allows only male horseshoe crabs to be caught and taken, will allow for a growth in the population of horseshoe crabs in the bay. Recent monitoring data shows that the number of spawning males has continued to increase significantly in the bay, even with the male-only harvest restrictions in place.

Monitoring programs are in place that will detect important declines in male to female ratios if fisheries managers decide to continue with the current management strategy.

But, according to Dr. Smith, it is important to understand that the harvesting of horseshoe crabs is not the only thing that is keeping their population from growing. Whether the horseshoe crab can ever return in their former numbers is uncertain. They are being threatened by other factors – consequences of climate change and habitat loss loom large on the horizon.

Censusing horseshoe crabs is an imprecise science, and interpretation of survey results may vary. Dr. Larry Niles, Chief Biologist, Conserve Wildlife Foundation, acknowledges the important efforts made by the ASMFC in the past ten years and the possibility that the horseshoe crab population may be increasing. However, Dr Niles believes this improvement, if not a temporary up tick in numbers, is not matched by other surveys done on the Delaware Bay shore where shorebirds are feeding.

Over the six year history of the spawning survey, Niles states there has been no improvement in the number of spawning females. More importantly, surveys of horseshoe crab eggs in New Jersey and Delaware, the food on which the red knots depend, have also shown no sign of improvement in population numbers. In 2007, New Jersey counts of the number of horseshoe crab eggs were the lowest in the history of the survey.

Shorebird biologists found a corresponding 30 percent decline in red knot numbers in 2007 compared to two years ago. Dr. Niles believes it is vital that there are no more losses to the red knot population associated with inadequate availability of horseshoe crab eggs on the Delaware Bay and will continue to argue for further harvest restrictions to assure increases in breeding female horseshoe crabs and their eggs so vital to the red knot.

And yet, it still may be too late for the red knot. Published population models of the red knot indicated that the bird will be at or near extinction in 2010 – just two years from now. Since horseshoe crabs take 10 years to reach sexual maturity, even the restrictions in place now may not be enough to increase this vital food supply for the red knots and ensure their survival. 

But, it is not only the survival of the red knot that is at stake. Like the proverbial canary in the coal mine, the red knots’ decline and potential extinction is a warning sign of larger consequences and danger to come. If steps are not taken to protect our unique ecosystems and wildlife, they may disappear forever. 

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 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 http://shorebirdproject.blogspot.com/, 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.

WEB SITES

Horseshoe Crabs

HorseshoeCrab.org
http://horseshoecrab.org/
Comprehensive Web site exploring the anatomy, evolution, conservation, and research on the horseshoe crab. Also visit http://horseshoecrab.org/act/act.html for information on how to get involved in helping the horseshoe crab.

Green Eggs & Sand Educational Program
http://www.dnr.state.md.us/education/are/ges.html
A Tri-State Horseshoe Crab/Shorebird Education Program for middle and high schools students.

University of Delaware Sea Grant College Program
http://www.ocean.udel.edu/horseshoecrab/
Web site designed to provide the public with research-based information about the horseshoe crab. Plus, information on artificial bait to replace horseshoe crab meat: http://www.ocean.udel.edu/horseshoecrab/Research/bait.html

Horseshoe Crab Research Center
http://www.nmfs.vt.edu/HSCwebsite/index.htm
The goal of the Horseshoe Crab Research Center (HCRC) is to provide information required to sustainable manage the horseshoe crab resource for the benefit of all resource users.

Dupont Nature Center – Red Knot & Horseshoe Crab
http://www.dupontnaturecenter.org/explore.html
Owned and operated by the Delaware Division of Fish and Wildlife, this center offers one of the best viewing areas for spawning horseshoe crabs and migratory shorebirds during the peak season.

Red Knots

The Shorebird Project
http://shorebirdproject.blogspot.com/
Larry Niles, featured in “Crash: A Tale of Two Species, and an international team of biologists who monitor red knots and other shorebirds blog about the ongoing news surrounding red knots and other shorebirds.

Friends of the Red Knot
http://mysite.verizon.net/vzeu3rwf/
Friends of the Red Knot is a club whose members are working to have the Red Knot bird placed on the Endangered Species List.

Shorebirdworld.org
http://www.shorebirdworld.org/index.php
Organization dedicated to promoting understanding and awareness of the natural history of shorebirds.

New Jersey Division of Fish and Wildlife
http://www.nj.gov/dep/fgw/ensp/redknot.htm
NJ Division of Fish and Wildlife’s page on Red Knot Population and Conservation.

American Bird Conservancy
http://www.abcbirds.org/abcprograms/science/watchlist/red_knot.html
ABC’s mission is to conserve native wild birds and their habitats throughout the Americas.

Birding and Conservation

All About Birds
http://www.birds.cornell.edu/AllAboutBirds/
All About Birds is Cornell Lab of Ornithilogy’s Web site for bird basics. Includes info on identifying birds and birding hotspots.

Audubon
http://audubon.org/
Audubon’s mission is to conserve and restore natural ecosystems, focusing on birds, other wildlife, and their habitats for the benefit of humanity and the earth’s biological diversity.

eBird
http://ebird.org/content/ebird/
A real-time, online checklist program for bird sightings.

Manomet
http://www.manomet.org/
one of the nation’s oldest independent environmental research organizations, Manomet conducts original research on natural systems and wildlife.

Defenders of Wildlife
http://www.defenders.org/index.php
One of the country’s leaders in science-based, results-oriented wildlife conservation.

Wildlife Conservation Society
http://www.wcs.org
Search the WCS Web site for a wealth of information about horseshoe crabs and red knots — as well as about how their fates are intertwined.

BOOKS

Harrington, Brian. The Flight of the Red Knot: A Natural History Account of a Small Bird’s Annual Migration from the Arctic Circle to the Tip of South America and Back. W. W. Norton & Company, 1996.

Crensen, Victoria. Horseshoe Crabs and Shorebirds: The Story of a Food Web. Marshall Cavendish Corporation, 2003.

This Teacher’s Guide accompanies the NATURE program Crash: A Tale of Two Species. The program looks at the interconnection between two very different animals — the horseshoe crab and the red knot — and the threats to their survival.

Lessons in the guide use the programs as a starting point for discussions and activities that focus on adaptations that help these animals survive, the ways that human activity can endanger different species, and the varieties of wildlife in your own community. This guide includes teacher’s pages and student activity masters that can be used with the program. Please photocopy the pages and hand them out to students in class.

» Download this guide

Download Instructions:

To download the Teacher’s Guides as PDFs, you must first download the Adobe Acrobat Reader, available for free on Adobe’s Web site. The Reader is available for most computer platforms, and once downloaded the Guide may be viewed onscreen as well as printed out.

Steps:

1. Download Adobe’s Acrobat Reader from Adobe’s Web site and follow the instructions to install it.
2. Download the Teacher’s Guide.
3. Open the Teacher’s Guide. If Adobe Acrobat is installed correctly, the guide will open automatically in most browsers. If the guide doesn’t open automatically, save the file to your desktop or to a particular folder, then open it manually.

Please note: This and other Teacher’s Guides are also available in print. If you are interested in obtaining printed copies, please write to:

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