What happened?

I’ve seen this red squirrel before and thought that my eyes were mistaken.  I’ve never seen a tail-less squirrel before.  He kept pulling apart the burlap around my fathers birthday present. Then he seemed to disappear for quite some time!  Now he is back and I got a better look at him through the zoom lens of my camera.  It almost looks like the tail simply “fell off”!  Has anyone else seen this?!!?