Thursday, June 04, 2009

Soldier Crabs revisited

The tides were low around lunch time again today, around the time I last saw the soldier crabs on the move, so I headed out to the tidal flats to take another look.
Sure enough they were marching across the sand in vast numbers.

The Ibis paid them no heed though, at my approach, they( the crabs) quickly started to dig themselves in again.
I was intent on observing behavior other than running like hell and digging a hole, so I skirted around them using some mangroves as a screen to get closer.

Dont let anyone tell you that taking nature shots is clean, dry, or in any way pleasant a majority of the time.
Sitting on the wet sand, keeping dead still, I was able to observe them at about 2 meters distance doing their regular thing...foraging, and fighting.

I found the postures they adopted rather comical, though wondered if this was a territory thing or if I was witnessing mating.
No crab came to harm during these encounters, claws held high with legs usually in matched positioning.

Considering the huge groups these strange creatures move around in, this behavior is rather sporadic and not an overly regular event.
I was not able to notice differences in the crabs performing these actions other than a slight variation of colouring on their sides (can be seen in the above shot).
All in all it was an interesting experience to be surrounded by so many of these crabs.
I made sure I didnt sit TOO still though.
They seem very efficient at cleaning up anything that does!
...and those Ibis?
Well, they could be found looking for worms brought to the surface by the recent rains.


  1. I was out on the sand flats with lots of soldier crabs around today too. I didn't see any of the interesting behavior you observed. Don't know why. Nice photos.

  2. Hi Mick,
    Thanks for dropping by :)
    I had to keep a real low profile for them to show this behavior.
    I would be interested to hear if you happen to see the same, and are able to notice sex differences in the crabs performing this bizarre dance.



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