it might sound weird but all this depends on your birds, the location of the pen, the weather, and countless other factors. When i see an answer to a post like this I usually take it as a generalization, what works for me might a be a complete disaster for you, and vice-versa. A perfect example of this is my doves and homing pigeons, I had one white homer that would sit inside my ringneck dove aviary and not touch a single bird, another white homer broke out of its cage twice and went on a dove killing rampages severing the necks.
