I dont know how valid this information is, but I did some researching for you and this is what I found.
Blue Front Amazon parrots were heavily imported from South America into the United States throughout the 1980's. Many of the importation quarantine stations are in California and Florida. Public protests of the exploitation of birds and wildlife, and motions in favor of the preservation of the rain forests, prompted new federal and international regulations regarding the importation of wildlife. In the early 1990's, the importation of wild Blue Fronted Amazons decreased dramatically.
Because these parrots have beautiful colors, tame easily, and talk well, they became popular pets in the United States. Psittacine breeders quickly discovered the tricks of successful propagation of this species in captivity, and captive raised birds occupy the majority of Blue Fronts now sold in pet shops. In general, birds purchased before 1990 are very likely to be imports, and more recent birds are likely to be hand raised.
Leg bands are informative. A round, stainless steel band, with an incomplete circular closure is a quarantine band. It has letters and numbers, such as AGC 289. The letters identify the quarantine station receiving the birds within the United States. The number identify which bird in the imported group wears that band. These bands are applied to the wild caught birds when they enter the United States via one of many avian quarantine stations. The bands are very tough, and difficult to remove, so most quarantine birds keep their bands for life. Flat bands can be applied by anyone to any bird, and are used merely for identification. Flat bands can have anything written on them. Welded closed bands are applied to baby birds, and usually indicate hand raised babies of captive bred birds. These bands usually have letters and numbers identifying the breeder, but can have anything the breeder chooses to have imprinted on them.
Breeder band identifications can be traced through local and national bird clubs and organizations. Your local avian veterinarian or pet shop is a good starting place in attempt to track a breeder band. There is not a national breeder band registry. Quarantine bands are applied by the USDA, and are carefully tracked. Such tracking is important, for in case of a disease outbreak, the USDA needs to be able to locate all exposed birds quickly. You can contact your local United States Department of Agriculture, Animal and Plant Health Inspection Service office. They are very helpful and responsive to disease inquiries. They may be less helpful for just curious calls.
I hope that helps at least answer some questions for you.
