My boyfriend and I are building a "small" aviary and plan on getting 4 cockatiels and are having a parakeet given to us by a friend. Will a 36"x60"x81" be ok for all 5 to cohabit nicely? Should we get another parakeet and keep them seperate? All are rescued so none are going to be babies. There is so much conflicting info out there I though it just better to ask experienced owners. Thank you!