Sunday, June 13, 2010

Crab Grab

The full and new moons bring "spring" tides; the highest highs and the lowest lows of the month. Logs, branches and other vegetative material that have accumulated along the shore get swept up and redistributed, leaving a debris line at the high water mark--rich pickings for the hermit crabs that feed on this detritus.

Most crab species molt in order to grow, finding a safe place where they can slip out of their old shell as they harden a new one over their soft vulnerable bodies before venturing forth, lest they becoming an easy meal for a predator. Hermit crabs don't form their own shell, rather relying upon the discards of others, typically sea snails. But competition for new homes can be tough in the intertidal real estate market, so it can pay to be creative.

I was sitting on the log where I typically enjoy my morning coffee, dividing my attention between the sunrise and the heavy flock of hermit crabs working the high tide line, when something unusual caught my eye: a disembodied walking crab claw, powered by a rather large hermit crab. Unable to resist, I picked it up and brought it back to the cabin to photograph and make a short video clip.