Good Lord! 60 birds in a 12.5 by 25 foot pen. What a recipe for disaster. I tried and I am done after this post. I will say this and just perhaps it will get through. The size of a covered flight pen is so the birds can exercise their flight muscles so when they are released they can fly and elude predators as well as not putting birds that do not like to be close together, close together. When blinders are put on birds they have to be removed before they are released. Too many birds in a flight pen will discourage flight practice because of mid air collisions in addition to encouraging cannibalism and disease. I continue to wish the lad good luck but I wouldn't bet on his chances.