When hunting mixed bag, load for the tougher bird, not the more fragile one. If my main quarry are pheasants, I load with 5s and make do with them if I run into quail or grouse. If my primary quarry are quail, il load up with #6 if there is a reasonable chance of finding a rooster. There have been times I've had low possibilities for roosters and then used 7 1/2 shot and was willing to pass on opportunities that would have been fine with larger shot.
