Like other posters have said, I’ve seen both Coturnix and Bobwhite maintained in aviaries with some of the calmer pheasants like goldens and flying birds like small parrots and finches, maybe doves. Apparently button quail and coturnix have value in aviaries as seed vacuums, eating all the seed that the other birds spill. Providing a huge amount of space for separate species to get away from each other is definitely necessary, and always assume they are vulnerable to disease + parasites, it’s definitely always a risk.
They probably do not do well with mammals, since many pet mammals can be aggressive towards birds. Maybe you could keep a tortoise with quail, but I think it might stress both of them out. I’ve heard of bantam chickens raising quail chicks, but I worry that adult quail would be at risk of attack by even the smallest bantam chickens.
In my quail pen, I keep a big slate above some mulch. In the summer, wood lice, crickets, and caterpillars enter to coop to eat detritus, and take refuge under the slate. In the morning, I lift up the slate, and let the quail feast!
