This is the classic "Large Dovey House" design. We bought the smaller one years ago and the doves used it every year, having multiple series of birthings each season. I assembled using #10 x 1-½" wood screws instead of glue, so the doves aren't exposed to the glue odor. I also prefer 3D printing to building with wood because I'd have to paint or stain it to make it last and that might be a problem for doves. If printed in the orientation I show, you should require no supports. The screw holes are sized for pass-through for the first component and self-threading in the second component of each hole set.
The author marked this model as their own original creation.