Wing entrapment idea.

[philsand]

I am wondering that if there was a rounded notch at the top of the entrance, modifying the SREH entrances, so that a struggling martin could slip the trapped elbow through, yet not make entrance easier for starlings. Maybe one at each corner.

[philsand]

Maybe carve out a little crescent at the place on each side where the round hole would be. Kinda recapturing the safety of the round entrance. I hope some researches this.

[Gauxt]

I would like some ideas on this subject also. Lost 2 adults last year and saved a 3rd. All connley II entrances.
Emil's sideboards sounds like an option but haven't tried them...…...