Poultry is different from any other livestock. There is no concept of pedigree in poultry breeding, and only "some" concept of general tracking of lineage (as in, "my flock is from Joe Smith's lines"). This is not necessarily a problem. Indeed it probably
. You just have to alter your expectations if you come from a background in breeding other domestic critters.
So what's the point of keeping an endangered bird if it's already bred out of its genetics? The best we can do is get a breeding set or two and cross and cull to get close to the standards, but that doesn't mean that the genetic line is intact. And if that's true there would be no way of re-creating said birds because the lines of birds that they were created from don't exist either. aaargh
There are two things here:
First is lineage. If your birds have a considerable proportion of blood descending from an old line, they are preserving as much of the old gene pool as is realistically possible. So while pedigree of *individuals* is not generally much worried about, pedigree of a *flock* (if I may twist the term to say that) IS a relevant concern... where the original stock was from, and what other blood may have been introduced since then.
Second is selection. Chickens are real bad at staying true to breed standard on their own. It can be argued what the cause(s) of this is/are, and whether it should be telling us something important or not, but for this thread the point is that it's just the way it IS. So no matter WHAT you start with -- even if you could go back in time and capture a flock of Colonial-era Dominiques, for instance -- if you just let them breed in a motley undirected fashion, they will soon drift away from what the breed is supposed to be. The same is true if you select carefully but for the wrong things. So what you need is someone selecting constantly and fairly strongly for the flock to stay true to the breed standard. It is not like, say, beans -- where you can plant this year's seed, grow them up, harvest seeds for next year, and do that ad infinitum with very little change in the product.
Also, remember that all chickens, of any breed, have the same number of ancestors
The point, I think, is to preserve what diversity there is TODAY, and try to keep it diverse, keep it from all swishing together into a single homogenized product that then gets selected-down for just a few traits and the rest is lost.
JMHO,
Pat