Here’s the nesting box I made for my five, now four, homing pigeons. It’s made from 1/2″ plywood, wood glue and 1″ common nails. The dimensions are 2 feet by 4 feet with a depth of 11 inches. The spaces on top can also be used as nesting spots. I finished with two coats of glossy, clear exterior Varathane. No front lip was added for ease of cleaning.
I realize now that the holes may be pitifully small, but I assume they can just take over an additional space if they want.
It has poop in it so I know they go in there, but it will be a few months yet before anyone is ready to breed. I’ve read they need to be about 8 months old and I think my birds are only 2-3 months.