Dealing with endangered species is very difficult for those of us working in museums for a number of reasons, not the least because the regulations were not written with us in mind and our needs (i.e., having objects made with part of endangered species) really don’t fit many of the laws’ options.
First, “birds of prey” are covered by several different laws. Eagles (bald and golden) are covered by one law and set of regulations, which are the most restrictive of any of the rules we need to follow. At this point if you do not already have a permit to “hold” eagles (or any of their parts) it is unlikely that you will be able to get one (that was a Presidential order back in the 1990s). The other species are covered by the Migratory Bird Act and the Endangered Species Act. These do allow for museums (as educational institutions) to legally have these birds (or their parts) in their collections.
Having said that, the main question is what outcome you are looking for. Do you want to have the confiscated feathers returned? Do you want to be able to have regulated bird feathers (or other parts) in your collection? Or do you “just” want to make sure that no further action will be taken against the museum other than the confiscation?
If it’s the last, then you need to work with the agent who confiscated the feathers. I don’t think the museum can get its record cleared, but you can probably get a final resolution that says it made a mistake, the feathers have been confiscated and there will no further action against the museum. I have a colleague who has gone through a customs confiscation (also cleaning up a predecessor’s mistake) and I will check with him to see how that was resolved.
If you do want to continue to have regulated feathers in the museum’s collection you will need to do research on the individual species, the date they were listed as endangered species and when the bird in question was killed (usually dated by the age of the object it’s part of). And that’s a whole ‘nother conversation.
Museum Association of Arizona