Monday, February 11, 2008

Horseshoe Crab Resource Roundup

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“Crash: A Tale of Two Species” premiered on PBS last night, a beautiful documentary about the grim story of how overharvesting horseshoe crabs may doom a migratory shorebird population. The film takes viewers from the red knots’ Tierra del Fuego wintering grounds to their nearly vacant nesting habitat above the Arctic Circle, explaining the vital role of Delaware Bay horseshoe crab eggs in the birds’ ability to survive their astonishing spring journey north. Anyone who cares about animals will be moved when one of the red knot researchers tries to explain why the little “beach robin” matters.

This happens to be one of the conservation issues closest to my heart. I hadn’t ever seen a horseshoe crab until I spent a college summer at the Marine Biological Laboratory at Woods Hole, Massachusetts. I was taking a course in marine algae and didn’t know that MBL was (and still is) a center for horseshoe crab research. But I noticed a few strange, helmet-shelled creatures washed up on the first ocean beaches I’d ever seen, and I fell in love. In the years since, I’ve traveled to witness the joint spectacle of millions of nesting crabs and 100,000s of egg-hungry shorebirds converging on Delaware Bay in spring. I’ve also assisted, with my family, in a nesting beach census (can you tell a male from a female horseshoe crab? It’s a cinch!), visited a classroom that raises juveniles, and written about horseshoe crabs whenever I could, in the hope of generating more support for their protection.

So of course I know a few books for your horseshoe crab reading pleasure. Here goes. . . .

For adults, I especially recommend a poignant new look at the ancient phenomenon of mass wildlife movement: No Way Home: The Decline of the World’s Great Animal Migrations. While not focused on horseshoe crabs or red knots, it puts the crisis these species face in perspective with lost passenger pigeon flocks and constricted wildebeest, caribou, and pronghorn herds. Wilcove, author of an outstanding history of North American wildlife populations (The Condor’s Shadow: Loss and Recovery of Wildlife in America), relates the current state of scientific understanding of how animals accomplish these feats of navigation and endurance. He also emphasizes that much is lost when a migratory species survives without room to roam, as with South Africa’s springbok. Wilcove writes, “What is gone is not the species but the phenomenon of the species, the spectacle of hundreds of thousands of springbok marching across the Karoo desert, kicking up great clouds of dust, as they wander in search of forage.”

Children have several wonderful books to choose from. For the youngest crab fanciers, I recommend Ruth Horowitz’s Crab Moon. It’s a gentle picture book about a 7-year-old boy, who quietly watches horseshoe crabs coming ashore to nest one moonlit night. Young readers looking for more ecological detail will appreciate Horseshoe Crabs and Shorebirds: The Story of a Food Web. Author Victoria Crenson describes how the food web connects the lives of horseshoe crabs, shorebirds, and many other wildlife species around the Delaware Bay. Another fine, topical picture book is Red Knot: A Shorebird’s Incredible Journey, by Nancy Carol Willis. Presented like an ornithologist’s notebook, entries begin in southern-most South America and follow the birds all the way north and back. Detailed illustrations accurately depict both behavior and habitat at each vital stage along the way.

The web offers reading and activist opportunities for all ages. Here are just a few:
The Shorebird Project follows an international team of red knot biologists as they track their movements from Tierra del Fuego to the Arctic. This blog is written by globe-trotting knot expert Dr. Larry Niles, featured in the PBS “Crash” film.

The Ecological Research and Development Group is a leading organization working to protect horseshoe crabs along the Atlantic Coast and around the world. Their website offers everything from basic horseshoe crab anatomy lessons to academic conference announcements, to invitations to participate in crab counts, information on the “Just Flip ‘Em” campaign, and contest entry rules for children designing crab conservation posters.

Children may especially want to visit the site Friends of the Red Knot. Students at a Green Mount School in Baltimore started a club to advocate for red knots in 2007 and are now conducting a letter writing campaign to have the birds children’s group that’s conducting a letter writing campaign to convince the Interior Department to add the birds to the Endangered Species list.

A lively teacher’s guide to “Crash: A Tale of Two Species” and the horseshoe crab-red knot relationship can be found at the PBS Nature website. I’m happy to report that the guide lists my horseshoe crab book (Extraordinary Horseshoe Crabs) for elementary students in its list of teacher resources.

I hope that “Crash”, one of these books, or maybe the sight of a tired but determined migratory bird this spring inspires you to get involved protecting not just individual wildlife species but vital relationships like those between ancient, helmet-headed crabs and migratory shorebirds.


Dave Coulter said...

Oh, you must have read my mind. I tuned in to catch like the last 5 minutes of that crab/red knot, and was bummed out I didn't see all of it! I will check out your links...thanks!

pinenut said...

Hi Dave,

I hope that you get a chance to see the whole film. It's beautiful, and so memorable that a few days later, my 8 year old made a horseshoe crab model in his clay class, complete with 10 eyes.

I'd especially love to hear from anyone who has read Crab Wars: A Tale of Horseshoe Crabs, Bioterrorism, and Human Health by William Sargent. Of course, I should get a copy myself. . . .

Swamp Thing said...

It was a great program! I also would like to read "Crab Wars." Great post!

David said...

I'm all for setting limits to horseshoe crab harvesting, but I don't believe that the red knots' decline in numbers is directly linked to harvesting of horseshoe crabs.

There are too many other factors involved. One of the most obvious is that fact that these birds migrate all the way from South America, where they have increased their use of DDT to help control their malaria problem down there.

pinenut said...

Hi David,

Thanks for your comments. I'm very glad to know about your horseshoe crab blog! I hope that you'll get lots of stories about them from your readers.

Though I agree that many factors are contributing to red knot declines, the evidence is strong that the precipitous decline in horseshoe crab egg density has led directly to reduced weight gain and hence reduced survivability among red knots. Even if they survive after a poor spring feeding stop on Delaware Bay, they have a much lower chance of successful reproduction in the summer. Here's a link to one of many articles on the problem, this one from the Littoral Society: .

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Dave Coulter said...

You might enjoy this bit of news: