I am new to Chuckers, I am new to birds.... Mine dont seem to be agressive at all. When they were small I had them with a few pheasnts but had to take the pheasants out because they trampled on Chuckers. Wasnt hurting them but it wasnt fair to the chuckers but they never said a word. I got them from Macfarlane, There actually chucker red legs which are some kind of cross, maybe that is why there not agressive. I have had them about 6 months and the only problem i had was a dog attacked the pen and killed 3 by biting off there feet and a few others got no toes or part of a foot missing, but they did let me give them first aid. They didnt want me to touch them at first but they calmed right down. The only problem i have is I cant tell which are males or females...