Lijian

That is a often looked over question but one of importance.  I personally feel that the birds take on the
developmental stages that the breeders dictate in their mating decisions.  Many long timers on this
list know what I feel  to be very important in the breeding of birmingham roller pigeons.  I feel as
Mr Pensoms' writings state,

 "There is no fixed order of mating pigeons together; that is to say, we do not mate father to daughter, mother to son, grandsire to grandaughter, brother and sister, first cousins, and so on, without good reason. We set our breeding pattern according to those individuals which are most adapted to the conditions of the life for which they are bred, a process  resulting only the survival of the fittest. It becomes necessary that breeders record everything pertaining to the physical qualities or the pigeons they breed in an extremely concise manner so that they can readily choose mates which are the most llikely to reproduce, to a large measure, the ideal which the breeder has set out to achieve."

Having stated that I would say that prior to a bird being mated the breeder must understand what it is that he/she is looking for. Many will tell you breed this to that but it really may be the exact opposite of what you really should be doing.  After one has a result set in his mind, the birds should be mated in a manner which will aid in the manifestation of those desired effects.

For this to happen the breeder must have a thorough understanding of what it is that brings those desires to being.  Pensom also covered this in his writings:

" To maintain it we have to study many things, and probably the key word is temperament.   Their performances are but an expression of thier existing emotions during flight, which vary according to the conditions under which they are trained and flown. Therefore we have to breed for this temperament, and same is portrayed in what we call expression.  Expression is the look in the eye and is helped considerably by the shape of the head, which also is of special design. Head shape and expression are also essential qualitities that have to be thoroughly understood. Size is equally important. and the only logical conclusion must be the smallest possible."

If we now take the text and decipher their meanings, we discover that one must:

1. Know what it is they are trying to achieve.
2. Possess stock qualified to be used to move one closer to that goal.
3. Understand the essentials that are necessary for that goal
     A) type or carriage
     B) muscle
     C) feather type
     D) balance
     E) Temperament/ Character / Expression
     F) How all of the above come together to make the good uns.

Knowing that birds perform according to their existing emotions, makes temperament an essential trait. The bird must be physically able to perform at a very high level of performance and withstand the physical effects of that performance. So the body must possess strength for velocity and tightness and balance for style. If a bird is engulfed in excessive feather the roll will not have the tight high velocity and proper appearance in the air.  So once we get through going over the essentials, we still need to understand how to achieve them.  Breed best to best. Fly hard and cull harder. Don't get caught up in justifying the stocking of a bird.  If the bird doesn't do it right, wait for the one that does. If you make exceptions you prolong your agony. Like begets like and the more you use birds that don't meet your full expectations the farther your goal moves away from reality. 

The earlier you want your birds to begin the roll the more mental ability they must have to control it!!  If the birds are not mentally ready to handle the roll the early onset of such will usually be met with a higher casualty rate amongst them.  The sound bird is better equipped to fight and deal with the rolling impulses until a time at which it is safe to roll. This is what we want. How do we get there?

Learn to read the expression of the birds and most importantly for the novice fly them and watch carefully.
Look for the birds that come into the roll early and maintain it. The ones that don't make mistakes, are always doing things right. These usually are the ones that are properly equipped with the right temperament. When you find them amongst the kit watch them and study them on the ground also.

You will notice that their demeanor on the ground is also very subtle. They look as if they are always at peace and aware of everything around them, even if they don't get excited about it.  They possess something' that you need to get to know.  It is really not hard but many make it seem mystical.  It only takes consistent, arduant observation to develop an eye for the right kind. Just remember CALM, FRANK and DARING. The good ones will possess that type of expression.  Breeding this type also having the proper body structure will lead to birds that can come in early, develop great velocity and remain safe while doing so.

Hope this helps,
Corey Salery