Monthly Archives: June 2013

Who Came First? The Shorebird or the Egg?

What do Delaware Nature Society staff members do when they all take a day off together? Go play outside, of course! At the end of May, we headed down to the Delaware Bay to see the migratory shorebirds and check out the horseshoe crab phenomenon. It was quite a sight to see thousands of horseshoe crabs all in one place!


Look at all of them!

LOOK!  Photo by Jim White.

So what’s the big deal about these horseshoe crabs anyway? Every year in May and June, horseshoe crabs converge on the Delaware Bay to breed during the full and new moons, as well as high tides. The Delaware Bay is known as a staging site for migratory shorebirds, a place between their wintering and nesting grounds where food is plentiful and the birds can double or triple their body weight before continuing their journey. The horseshoe crab eggs that are laid are an important food source for these birds as they stop here on their way to their Arctic nesting grounds.

The first stop on our outing was at Slaughter Beach. Abbott’s Mill staff member, Elliot, taught us about the horseshoe crab migration and the interdependency between the horseshoe crabs and the migrating shorebirds. We spent some time looking for horseshoe crab sheds and even got to tag one of the horseshoe crabs!

Scientists can track where the horseshoe crabs travels by tagging them and hoping someone finds them and reports them later. Photo by Jim White.

FUN FACT: Did you know that horseshoe crab blood is really important? Horseshoe crabs are harvested for their blood because it is used in medical testing to ensure that drugs, vaccines, or other medical devices are free from bacteria contamination. Staff member Jim White extracted some horseshoe crab blood to show us how quickly the blood coagulates, or solidifies. It’s also a very bright blue color!

DNS staff member Jim White drawing horseshoe crab blood. Photo by Christy Belardo.


Next, we did some birding at the Dupont Nature Center and as we drove along Port Mahon Road. (Pronounced MAY-hon).  We got some great looks at the shorebirds throughout the day, check out these pictures!

So many Semipalmated Sandpipers in flight! Photo by Jim White.

Ruddy Turnstones. Guess why they are called turnstones!  They actually turn over stones and other debris with their upturned bill!  How cool is that! Photo by Jim White.

Anna likes Double-crested Cormorants because she thinks they look like dinosaurs! Photo by Joe Sebastiani.


See all those little green dots? Those are horseshoe crab eggs, and these Semipalmated Sandpipers were having a delicious lunch! Photo by Joe Sebastiani.

I was most excited to see the Red Knots on this trip because I’d never seen them before.  This colorful bird has declined dramatically in recent years, partly due to the overharvesting of horseshoe crabs, who’s eggs they eat along Delaware Bay.  However, this season there has been a higher count of Red Knots on the Delaware Bay than scientists have seen in a number of years!

The Red Knots look very similar to the Semipalmated Sandpipers, but you can see they are much larger and have a red breast. Photo by Joe Sebastiani.

It was such a great day to spend some time away together as a staff and just be outside! It was a lot of fun learning about the horseshoe crabs and learning how to handle them. It took a little getting used to…

It was slightly alarming holding the horseshoe crab for the first time, especially when it was pointing its tail at us! They are actually harmless and fun to hold.  No need to be afraid!  Photo by Christy Belardo.

…but after the initial “yikes!” moments, Anna and I had a blast taking a closer look at these ancient animals!

Photo by Jim White.

Two thumbs up for horseshoe crabs! Photo by Brian Winslow.

By the time you read this, many of the shorebirds we saw will be winging their way to the arctic to nest.  Some of them fly non-stop for thousands of miles to get there!

Just like these shorebirds, Anna and I will be spreading our wings and flying onto what’s next as our year-long internship comes to an end. We had an absolute BLAST writing for the blog this past year; we hope you’ve had as much fun reading our posts as we’ve had writing them! Don’t worry though, we will still be around this summer teaching camps and plan on occasionally guest writing for the blog. We hope you continue to have fun outdoorsy adventures, and we’ve encouraged you to as find as much joy in nature as we have!