Sand in the Coffee, Vol. 116: the ghost crabs, and the beach after dark

Walk down to the water tonight about an hour after dark, turn off every light you’re carrying, and stand still for thirty seconds.

The beach will start moving.

Not the surf. The sand. Pale shapes, some as big as your palm, going sideways, fast, and stopping dead the moment you shift your weight. Those are ghost crabs, and they’ve been under your beach towel all week. Every beach has a night shift. This is ours, and October is about last call. Once the nights turn cold, they slow down and hole up for the winter.

what you’re looking at

The ghost crab is the color of dry sand, which is the whole trick. Its eyes sit up on stalks and see nearly all the way around. It can run about ten miles an hour, which doesn’t sound like much until it’s headed for your bare feet. Its scientific name, Ocypode, means “swift-footed,” so the scientists were impressed too.

Those holes you’ve been stepping around all day are theirs. They run from the size of a quarter to the size of a golf ball, up in the dry sand, usually with a little spray of dug-out sand fanned to one side. A burrow can go down as far as four feet. The small crabs dig close to the water. The big ones live up the beach toward the dunes, like anybody who’s been here long enough to afford the better lot.

They breathe air, but through gills that have to stay wet. That’s why you’ll see one sprint down to the wash line, let a wave touch it, and sprint back. It can’t live underwater. It’s a land animal with a wet commute.

They also make noise. Researchers worked out a few years ago that a ghost crab can growl at a threat by grinding the teeth in its stomach. I don’t have a joke for that. I just think you should know it before you crouch down.

how to do it right

When: Sunset is around 6:30 this week. Give it an hour past that, until the sky is fully dark. Warm and calm is the good night. If a front has just come through and you want a jacket, the crabs have made the same call and stayed in.

Where: Any open stretch of Gulf beach, Florida or Alabama. The sand in front of your rental is fine, and an Orange Beach public access works exactly as well as one on Perdido Key. The national seashore at Johnson Beach keeps gate hours, so check them before you plan a night walk there. Work the zone between the last wave line and the foot of the dunes, and stay off the dunes themselves. They’re protected on both sides of the state line, and on the Key they’re home to the Perdido Key beach mouse, an endangered animal that also works nights and doesn’t need the company.

Light: This is the rule that matters. No white light on the beach. Sea turtle season runs through October 31 in both states, late nests are still hatching, and a hatchling steers toward the brightest thing it can see. That’s supposed to be the sky over the water. It shouldn’t be your phone. Use a red light, aimed at the sand, and switch it off when you don’t need it. A headlamp with a red setting costs fifteen to twenty dollars, or about two Bushwackers (the frozen rum milkshake this coast runs on). The crabs seem to mind red less, too.

What to do: Nothing. Stand there, watch, and let the kids narrate. Don’t chase and don’t grab. They pinch, they’ll drop a leg when they panic, and a crab in a bucket is just a crab having the worst night of its life. Inside the national seashore, bothering the wildlife is against the rules anyway.

the morning edition

If your crew is asleep by dark, go at 7 a.m. and read the paper instead. Look for fresh holes with damp sand flung out beside them, and tracks like tiny stitching running from the burrows down to the tide line and back. That’s last night, written down.

The live cam will show you the surf all day long. This part of the program isn’t televised.

one favor

Before you head up for the night, fill in the holes your kids dug and carry the chairs in. Orange Beach and Gulf Shores call it Leave Only Footprints: gear off the sand by an hour after sunset, holes filled. Escambia County has a leave-no-trace rule of its own on the Florida side. The reason is practical. A knee-deep hole in the dark does to a turtle hatchling roughly what it does to your ankle.

The crabs dig their own and know where every one of them is. Leave theirs alone. Fill yours.

Check the wind on /beach-today/ before dinner. If it has laid down and the evening’s warm, that’s your night. Go stand in the dark for thirty seconds. They were here first, and they’re faster than you.

— Chris

P.S. If you run a place on the Key or over in Orange Beach and it’s already on this site, the listing is yours to claim. Free, and it stays free: /submit/claim/