12GA ID, maybe blanks or related

This ID request came in and I wonder what these are.
The rounds are all very light and seemingly do not contain solid projectiles.
The left one has a white plastic ring with a hole in the centre which seems to be closed by a translucent foil or disc, underneath there is something blue, could be dye or so.
The two others have cardboard closing discs.
None of the 3 have any markings except for the headstamps (which most likely mean nothing).
Cartridges have shown up in different locations and making any conclusion from this is impossible.
No further info available.

OAL is:
left: 66.3 mm
centre: 60.3 mm (cardboard case)
right: 62.8 mm


Anybody knows more?

They could perhaps be bird scare?

I hoped at least the left one would be recognizable?