That's a fair question, so I'll give you an answer....even though it's not really your business (whomever you are).
I'm constantly receiving e-mails, phone calls, etc. from people wanting to buy birds, eggs, whatever.
Earlier this year, I had made a decision to quit breeding a few breeds. At that point, I let a few select people know that certain birds were up for grabs...so to say. My Chinas, Cayugas, Saxonies, Embdens, and Pilgrims were re-homed to other breeders who specialized in those breeds, or who wanted a start. I chose to keep the Orps, Ameraucanas, Indian Runners, Khaki Campbells, Welsh Harlequins and Crele OEG. Those were the birds that I started with, and the ones that I chose to keep.....even though I had people pressuring me for them also.
About two weeks after I re-homed the chosen few, I came home from work on a Monday and found the rest of my large fowl and ducks gone. There was NO carnage, no breaks in the fencing, and absolutely no trace. I just sat down and cried. A few days later, three drakes reappeared. Don't know where they came from or where they were.
Dumbfounded, I assumed it was some sort of predation. It was a couple days later that it was proven to me by a few friends, that it was a two legged predator. I simply did not believe it. Why would someone go to all that trouble for a few birds? Once we put the dollar figures to it, it became apparent.
Bottom line, it's easier to tell people that the dogs ate them. It keeps the questions to a minimum. Besides, would you want the world to know that someone walked on to your farm and robbed you blind while you were at work? Have you ever been burglarized? It's violating!!!! It's embarrassing, and a lot of other things. And, how serious do you think that a small town PD takes chicken thieving?
It's just freaking easier to tell everyone that the dogs ate em. But, I suggest that you bump up your own personal security, lest it happen to you. I lost 10 years of selective breeding for all intents and purposes. Feel free to gloat, but remember....what goes around, comes around.
Good luck to you!