My birds, I leave their secondaries and only clip their primaries. They can fly a little but its not enough for them to get over the fence (they can only go up halfway). Since galliformes are ground birds, they spend most of their time on the ground and are fast on their feet and so as long as there is plenty of cover nearby, they should be safe from aerial predators (after the first fly-by incident that is; if you have a large tree where hawks can hide, don't even bother letting your birds out). Can't say the same for ground predators though. My mountains are pretty dumb when a cat comes into the yard; they are not well genetically programmed in the head for ground predators compared to aerial. If you were referring to quail as in coturnix, disregard what I said because coturnix are even less fit thanks to all the heavy domestication.