I have 17 Jumbo Ringneck pheasants that are 3 weeks old there brooder is getting really tight When are they old enough to go outside to the flight pen? Should they go right to the flight pen or should i build the a smaller outdoor pen until they get a little bigger. Right now the tempature averages about 75 degrees during the day and will keep going up as the weather warms. There brooder right now is 85. Thanks!