Spurs don't develop on cockerels till about eight months old or older. That bump you see is on both boys and girls. The comb seems to be pinkening up toward the back. Are the legs particularly thick, Adam? That's one way I could tell with my RIRs the last time.
Adam, I keep looking at this one, and I just can't make up my mind. Could definitely go either way, but the legs don't look really thick, like the cockerel I hatched from Julie's eggs last year. Possibly a pullet there.