As a novice myself, I should probably not interject... But... I think 4 is a bit much. I did read that too. I did A LOT of research. What... 4 books, and Internet searches galore. The more common thought is 2-3 square feet per bird. Now I think 2 square feet is a bit tight and might be inviting some behavioral issues. But I think 3 square feet is a great compromise. Just my opinion.