my vote doesn't count because I am too new and couldn't figure out why my year old hen wasn't laying until I realized it was a roo, so I am probably wrong here, but I vote roo.
Thats a roo. I have several that look just like him. In my experience buff orps can be a little slow in getting the shiny feathers that give them away as roosters. I have 3 5 month old boys and 2 look like over gown hens as they are not shiny yet.
definitly a female because by now you would see the spurs if it was a male. also by now the tale feathers would have some that would be a bit longer and curled down a bit. The feathers near the tail but still on the back would be thiner and hanging down kind of like hair. your chicken definitly does not any of these characteristics that males usually have. so i vote pullet!!!