WyandotteLove1
In the Brooder
That's a beautiful cocky you got there! I love 'Pecker'!The Development of a Buff Orpington Cockerel
The upper image is the cockerel, the lower image is the pullet. The cockerel's comb is ever so slightly more developed than the pullet, you almost need to be holding one in each hand to tell. Once you develop an eye for it, the difference becomes readily apparent. There is just a hint of redness beginning to appear in the cockerel's comb.
Mostly, you will notice a fearlessness in the behavior of the cockerel. He will be the first to great you. He'll run right up to you, putting himself between you and the rest of the flock, he did when the upper image was taken...then sorta give you a, "Why did I just do that?" kind of look. In the above images, they are at what I call the Raggamuffin Stage, about 4 to 5 weeks of age.
The lead bird in this image is the cockerel. His comb is redder and more developed than the pullets. 7 to 8 weeks in age.
In this image the cockerel again has the redder more developed comb at 8 to 9 weeks of age.
Once his hackles started coming in, it was pretty easy to tell which was the Cockerel. Also look at his tail feathers as compared to the pullets in this photo. They are right around 12 to 13 weeks in this image.
And the dead give away is when the Cockerel starts making weird raspy chortling noises as he is learning how to Crow. He is right around 13 to 14 weeks in this image.
...his name was Pecker, by the way.

