I found quite a few little bones at the creek the other day. The last time it rained the creek flooded a bit and washed all of these goodies in. All are bones from small mammals, most likely raccoons or possums, except for one (the last two pictures in the set). It was a very damaged bird skull. I’m 95% sure it was a turkey but since I couldn’t be 100% sure (too much of it was missing to really be able to tell) I took a couple of pictures and then left it where I found it.
You cannot legally possess any part of a bird protected under the Migratory Bird Treaty Act, which covers just about all native US birds. So in my book, if you don’t know what it is, it’s best to leave it alone.