I like the idea of deep nest cavity. Entrance can be made to where it will be difficult
for starlings to crawl in. When it comes to feeding the young, I think the parents can
feed all of them equally instead of the strongest hatchling blocks the weaker from
getting fed. The only drawback I can see with the deep cavity is keeping the nest
dry.
This is why my housing was made to have the entrance half an inch above the main
Floor and the nest insert an inch above the floor. I have to remove my own version
of SRE to expose a large slot opening that can accommodate three to four young PM
to stick their heads out at the same time. The trouble with this is if there are five or
more young PMs , mostly likely the weaker do not survive.
My Tunnel SRE:
