While on a recent cruise I saw a pigeon walking on the deck. Where I come from they are called " flying rats." The reason was the diseases that they carried. But possibly this was a disease free racing pigeon or even a messenger pigeon that had decided to hitch a ride on the ship to the next port. We were passing by Puerto Rico at the time and I have seen pigeons at that port so I figured Puerto Rico was its embarkation point. I didn't see a tag on its leg which may have helped to determine where it had originated. But as I watched it walk around I remembered an old story I had heard about how the US Post Office would ship pigeons for pigeon racing organizations. I figure that there are some retired US Postal employes cruisemates who could give me an answer concerning this question. I know that at one time the Postal Service did ship the bricks for an entire house and supposedly they still may continue to ship baby chicks.