"As we watched the feeding shorebirds, we were keenly aware that their survival depended on the survival of the crabs."
By Lola Oberman
Ted and I are a lucky couple. Our shared admiration for birds gives focus to our lives and travels. We have a special fondness for shorebirds in all their varieties, so we’re also lucky to live within driving distance of Delaware Bay, a mecca for migrating shorebirds.
Early in our birding days, we discovered an ideal spot for close-up views of shorebirds in migration. So we made it an annual ritual to go to Port Mahon Road in the small town of Little Creek, Delaware, toward the end of May or early June.
Knowing the heroic effort expended by the migrants in reaching this stopover, we thought the least we could do was to be there to greet them — and appreciate them.
This time of year was also when female horseshoe crabs would come ashore to lay their eggs on the beach. The greenish egg clusters provided a feast for shorebirds on their 9,000-mile journey from the tip of South America to their Arctic nesting grounds.
The strange-looking crabs are often described as "living fossils" — and for good reason. Their ancestors predate dinosaurs, and their very appearance marks them as prehistoric.
The horseshoe shape of their hard shells gives them their name. On close examination, you might find all 10 eyes, which are useful for seeking light — and mates. But the crab’s most distinctive feature is a long spiky tail, which serves as a sort of rudder. We had seen these strange creatures before, of course, but never in such numbers as we saw along Port Mahon Road.
Yet our main interest was not in those weird-looking crabs, but in the masses of shorebirds that came in swirling silver flashes above the surface of the bay. Until they swooped in for a landing, we could believe they were all one species.
But when they alit and began feeding on crab eggs, they came close enough to reveal their identities: least and semipalmated sandpipers, clownish turnstones, and larger red knots. There were occasional surprises: black-necked stilts or willets wading in tidal pools. Gulls and terns added variety to the mix.
Only feet away from our car, they moved along shoulder to shoulder, oblivious to everything but the feast that awaited them.
Cars crept along as other birders paused to focus binoculars or take close-up photos. Pickup trucks also were out in numbers, their occupants leaping out to grab horseshoe crabs by their tails and heave them into the truck beds.
We learned that these crabs were a vital part of the local economy. They provided bait for fishing, and some said the shells were crushed to make fertilizer.
We were dismayed, though, to see harvesters wade into the water to capture crabs that hadn’t yet reached the beach to lay their eggs. And as we watched the feeding shorebirds, we were keenly aware that their survival depended on the survival of the crabs.
As years went by, we saw the nature of Port Mahon Road change. Erosion is inevitable, and as the shoreline receded, the road became littered with man-made efforts to hold back the tides. Rubble from broken concrete blocks and rocks made the beach less accessible to cars — and to horseshoe crabs.
As the crabs diminished, so did the shorebirds. Word went out in the birding community: It's not worth the trip.
Shorebirds (and horseshoe crabs), however, still gather along other Delaware Bay beaches. Most of them, we hear, are on the New Jersey side. It’s a longer drive, with more walking involved, but for those who love shorebirds, it's well worth the extra effort.
But we look back to the golden age of Port Mahon Road with a touch of sadness.
Visit the Delaware Bayshores
See images and video of migratory birds and learn more about Conservancy preserves on the New Jersey shores.
Watch a video about horseshoe crabs and learn more about Conservancy preserves on the Delaware shores.
Passport to Nature
You’re invited to travel along as we explore our region's top nature destinations and conservation stories. Discover these special places and meet the people who are protecting and restoring nature.