“This is a fab feeder for garden birds, we have it in a covered bird table with mesh to keep the less desirable critters eating the Robin Mix, which is loved by many species..”
The Compact Ground Feeder Tray is designed to keep bird seed off the ground.
As it is a tray, then any birds or squirrels can access it.
If you wish to keep the bigger birds and squirrels from getting to it I would suggest getting the small mesh ground guard to put over it.