Hi..

Well, I didn't know they would abandon a tube, but this one may have done so. I
saw a feather cluster in that little cave, and it was gone tonight. If it
reappears, that's what's going on.

In the 70s some of my feather dusters from the Mediterranean Sea were
able to (re)build their tubes using mud, clay-fine sediments and sand
but it seemed to be stressfull to them..

cu
Marco