Even de letterlijke tekst uit het blad Birding World 21:1,artikel "2007: the Western Palearctic Year":
"Canvasback Ayrhya valisineria The first for the Netherlands, the regular male first seen in 2003, was present at its lake in the dunes near Castricum in both winter periods. Interestingly, a recent photograph of the bird wing-flapping appears to show for the first time a small strip of metal or plastic around a bone in its wing. Thanks to information provided by C.S. Roselaar, this appears to be virtual proof that the bird is a genuine vagrant from North America. The strip in its wings appears to be the remains of a patagial tag, frequently used by the US and Canadian Wildlife Services. The full tag is a coloured plastic flap, with a number which can be read easily in the field. It lasts for only one or two years (which is as long as Canvasbacks tend to live in North America, due to hunting), and then, typically, it tears off the strip that connects if to the wing, so that the strip is the only part remaining. Such patagial tags are not used by wildfowl keepers, so the bird is surely of Nearctic origin. Since Canvasbacks ar bred in captivity, there is a little chance that the bird was captured in the wild with its strip still attached and then transported to Europe (information provided by Arnoud van den Berg)"