I still don't understand the rejecting of ship-assisted birds. If the bird lives on the ship on its own, without being put in a cage, where is the problem? Ships are a fact of reality of today's world. With that logic, people should be investigating whether the bird was aided by the presence of roads, railways or high voltage wires in its navigation towards the point of observation. A merchant ship is basically a road over the water, it's just hard to make it fixed.