Well it's finally warmed up somewhat so I was able to add a window that can open to provide some extra ventilation at the high end of the single sloping roof:
And, although I don't know exactly how high the nests are going to sit, I've added framing for an egg door. The hole has yet to be cut but I'm hoping to be able to change out the water/food through this door as well. Is that a wise idea?
U may want to flip how the vent opens. So it can be open during the rain, when the leaves fall and so other birds do not try to nest in the opening.
opening from the bottom instead the top shields it from the weather but still allows plenty of ventilation. U may consider a grate opening on the opposite wall and low to the ground providing cross ventilation. Flows int he low and out the higher one.