Our pet cockerel Bottom, a large Buff Orpington, dislikes Wyandottes. All Wyandottes and only Wyandottes, colour not important. He chases them away or attacks them, which must be very confusing for them, being part of the same flock. The oldest, Lulu, is 3 now and has been chased away every day for the last 2 1/2 years. It hasn't distracted from her laying but it could easily do. Fortunately for her he is only around 3 hours a day.