Go see horseshoe crabs mate tonight

Fire Island Horseshoe crabs mating

“The full moon in June” is known as the best night to see horseshoe crabs mating on the beach at high high-tide. Tonight’s that night.

Horseshoe crab studies show that the full and new moons in May and June draw in the most horseshoe crabs to beaches along the east coast, from Maine to Florida, but especially around Delaware Bay. (I recently found a beach on Fire Island with 2,000 mating horseshoe crabs) Tonight is the peak of the horseshoe crab watching season–though if you miss tonight, you can go check for the next few nights as well.

The crabs are drawn to lay and fertilize eggs right by the water line, usually in a protected bay. The exact mechanics of what brings them when and where are still being studied. The eggs hatch two to four weeks later–if they aren’t eaten by shorebirds. But they are so teeny that they can’t be tracked to show biologists whether they go back to the beach where they hatched.

If you’re not up for going out in the middle of the night, come by in the morning and flip over some stranded crabs. It’s an oddly satisfying task. All the mating crabs are at least 10 years old, they’re population is dwindling because they’re used as bait and the simple act of turning them upright will give us another breeding crab.

Volunteer for the New York Horseshoe Crab Monitoring Network


horseshoecrab Where to SEE HORSESHOE CRABS


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