How many jumbos can fit in a 7' x 20'' colony pen? the person i got the plans from says he puts 70-75 birds in a pen, but that sounds really over crowded to me, i know some say you have to see what works for your birds and that very true but im just wondering what is a good number for a pen that size? i want to see how many can fit in that colony pen because im thinking bout doing some re-modeling to the plans if i dont like the number of birds that can go into that cage.