No offense taken Jed, and you're right, I'm not a FI, but hope to be soon. Suggest all you wannabes get your ppl's quickly!
You're wrong about weight though..it can of course change, simply through acceleration for instance.
Mass is a different matter entirely, as somebody already pointed out earlier in this thread.
The geese's energy keeps them flying, they are not 'supported' by the air. If they stopped expending energy they would land very quickly.