As part of the pre wedding events for my nephew's wedding in Sarasota, Florida, a few years ago, there was a golf outting. My brother had just hit his approach shot onto the green. I was standing just off the green. A large black bird then swooped down onto the green and picked up my brother's ball and carried it up into one of the trees behind the green. We mentioned this to some people working in the pro shop. They told us that is not unusual. Others have lost such things as watches(Rolex) and car keys. Perhaps there could be something of Amelia's in one of the trees on Nikumaroro?
I edited my original post on March 14, 2013, by changing blackbird to black bird.