Now You See Me . . . Hawaiian Sand Crabs…by Brad Marks

With the day after day pressures subsiding I’m finally getting to work on Linda’s .. I mean my to-dos. Tops on that list is to battle the leaf invasion that has managed to break through my first line ranks and now pouring over the castle walls with reckless abandonment. The paired night (or high wind/rain) task is to get caught up on the Mothership with some very late race recaps and more than likely some haunt tutorials sprinkled in. While I’m tending to those, S.W. Brad is ready with a “ghostly” observation from the Hawaiian Islands.

Take it away Brad!

On the first morning of our first ever vacation to a tropical island in 2000, the last thing you might think to do is to rise early.  However, when your body clock is off by five hours and thinks it’s noon, you get out of bed even though the sun isn’t up yet.  (BTW, in the tropics there’s only a little more than 13 hours of sunlight in the summer, and up to 11 hours in the winter time, go figure) Ambitious you say?  Jet lagged I say.  At the time, I was in the habit of having a mug of honey ginseng green tea with a dash of local honey in the morning before work.  Jan had already been awake and moving for an hour or more.  After steeping my first mug of tea for the day, I walked the 100-feet from our condo to the beach.  Lucky for us, the condo on Kauai was on a beach on the east side of the island, which means we’d get a perfect view of the sunrise each morning.  My primary goal that day was to watch my first Hawaiian sunrise and see if the green flash was a myth. (It’s not a myth, by the way, check here as one of a hundred potential resources)

As I stood watching the sky brighten in anticipation of sunrise, I noticed a lot of sand seemingly moving by itself.  I worked my way closer to see if I could figure out what was happening. 

As I drew near, I saw all of these busy little crabs excavating their burrows.  Hawaiian sand crabs are technically called “pallid ghost crabs” or Ocypode pallidula.  These crabs are small scavengers (mostly less than 3 cm, or just over 1”, shell width) that live above the tidal line in the sand. They are indigenous to the Hawaiian islands and are active during the early part of the day.  They are called ghosts because of their ability to seemingly disappear from sight, side-stepping at speeds up to 10 miles per hour.  Ghost crabs have been known to burrow into the ground, but I didn’t see this behavior from any of the crabbies on either of our trips to Kauai.

We saw these little sand crabs each morning on the beach at sunrise.  The crabbies were busy emptying sand from their burrows.  One front claw is much larger than the other and acts like a scoop shovel.  Each crab could toss the offending sand several inches, even though they’re just over 1” across when fully grown.

One crab on our next trip to Kauai in 2005 wasn’t just emptying his burrow.  He (or truthfully it could have been a she) was carrying the sand and throwing it at another crab’s burrow with a fair amount of accuracy.  He (or she) would then scurry quickly back inside its burrow.  Then I noticed the other crab emptying its burrow and, I kid you not, throwing sand back toward the other crab’s burrow.  I never quite found out if this was a territorial dispute, a dispute over a potential mate, or something to do with differing sports team loyalties.  The sand throwing went on for several minutes until the sun rose.  I didn’t notice as much the first day, but made it a point to watch the rest of our vacation.  At nearly the exact time the sun crested the horizon (missed the green flash again, but did see it other times), the crabs all stopped for a brief moment to face the sun.  What seemed like minutes (in reality was probably only a few seconds) nobody moved, not even me.  Once the first crab came out of its sun trance, the rest quickly busied themselves with a few last throws of sand and retreated into their burrows to escape the heat of the day.

I had a hard time getting usable photographs of the ghost crabs.  Keep in mind, it’s early in the day, and I’m trying to hold a camera and a mug of hot tea.  Eventually, I set the mug down on the sand and tried to keep the crabs in the viewfinder.  I gave up trying to track them moving on the sand.  Instead, I focused on the opening to their burrows and when someone showed up, I started clicking off photos.  Yes, I had a fair amount of blurry moving crab photos and empty burrow openings.  But every now and then I would catch one with a clawful of sand.  Then he’d throw it out in a fan formation.  Or in the next door neighbor’s burrow. 

I think this one was just watching everyone else fight over sand.

Thank you very much for reading.  If you want to see more crabbie photos, visit here.

Thanks to Jan and Allyson for proof reading, re-reading, and editing.  Again.