We have this problem in the winter, they seem to go away for the summer. Tried shooting at them but this didn`t work anyway. A radio on during the day worked for a time but kept forgetting to switch it on, or changing the batteries. Made myself a scarecrow with a bright pink hat, man sized, called her Gloria, and put it next to the pop hole. This worked quite well and the chucks thought she was harmless and ignored her, my chucks are bombproof anyway. Put the scarecrow in the shed for the summer and out she will come when the starlings come back for the winter. Hope it works again this year.