The BOWL JUST adds convenience, AND IS NOT A NECESSITY. It contains the squabs from falling out, as well as keeps them close together when small, and under parent for warmth. If the nest area is elevated, you can fashion some makeshift border from boards or whatever on hand to keep LIl Junior from falling out of balcony.I’m back y’all! The pigeons kept pushing the bowl I put up for them off of the nesting site, and now they’ve started building... View attachment 2050549
I always see them selecting sticks.
I would not have concerns about splayed legs from your nesting area. It is not like they are on a SLIP, AND SLIDE surface. I had squabs that were hatched, and raised in a bowl nesting area, and both of them developed splayed leggs.

BTW,, my thinking on feral pigeons making not such great nests, is,,,, they do minimal just to keep eggs from rolling of ledges
