Looking at Greenfire farm's line of partridge orpingtons they imported, I'm guessing by the color of the males that they are a pullet line. I just asked a friend if her birds were a male line or a female line because the male had so much color/pattern in his breast. I remember seeing a pic somewhere of a pair of birds that produced one of the best partridge rock pullets at a show in the UK, the female had amazing pattern and the male looked more like a New Hampshire with some smuttyness. I never breed anything for male/female lines, too much trouble. With the sumatras, we just have to keep the tails high enough in the females to keep the male's tails above horizontal when they're younger so that they will lower to horizontal as his tail grows