It is possible. chickens are very sensitive to light.I took the tarps off the run a couple days ago. It's under cover of trees and has shady spots all day, so that's nice. But what a difference! I remember thinking when I put the tarps on in the fall that it was dark and gloomy under there. Now it's bright and cheerful. Definitely going to put a clear roof of some kind on it this fall.
I'm wondering if that gloominess is part of why my pullets didn't lay last winter.
We'll be moving the coop and run to its summer home in a couple weeks. Unless I convince DH to leave it up here by the house year round. I'm actually thinking that might be the better spot. Yes, it's cooler down by the garden; you can feel the temp drop as you walk down the hill. But it's shadier and breezier by the house. I can create the shade with the tarps, but I can't make the breeze. The air is much stiller in that little valley.
I remember a post from years ago where the hens were in darkness most of the time. The poster had to add lights to the run for them and it was not the winter.
Supposedly they only need enough light to see several feet in front of them, so not too much light.