Songbird Essentials PMCA Excluder Ultimate Gourd Modified Excluder The Excluder Gourd is a new product designed for the benefit of the purple martin. The excluder gourd offers two patented entrance holes U.S. Patent number 6513454 and the crescent to exclude the European Starling from nesting. The closure cap is a necessity for doing nest inspections. The two center line hole punches on the gourd recommends 5/8 inch distance from the porch to the bottom of the entrance hole, however the porches may be attached at different levels at the landlord's discretion. External owl and hawk guards may be purchased as an accessory item. All excluder entrances work well for discouraging the European Starling. Since the original Excluder was introduced, it has been sold only as an accessory item on doors for purple martin housing. The New Excluder Gourd is the first manufactured product to offer per-punched excluder entrances. This item ships from a separate warehouse and may require extra time for delivery.