Convert the entrances on your plastic gourds with these SREH Conley II entrance plates.
SREH are the best way to prevent starlings from being able to enter your martin housing. Install these flexible plastic plates by using either screws, bolts, or even pop rivets which are NOT included.
Plate is 3 inch x 4 3/8 inch. Hardware not included, sold in 6 packs. Pre-drilled holes.
As SREH are wider than round entrances, you will have to enlarge your gourds original entrance.

Protection from the destruction that can be caused by European Starlings is easy and convenient with these doors.