Thank you, Hector and Allen, for making this discussion public.  Very 
interesting to this amateur.

As someone having seen the Barnacle Goose, I second Hector's 
observations insofar as feather
wear and banding are concerned.   Ditto on association with (obviously) 
wild birds,
and exhibition of 'wild bird' behaviors.  



hector galbraith wrote:
> Allan, 
> Re the barnacle goose: my personal philosophy about potential escapes is
> that, unless a bird is wildly unlikely to be a genuine vagrant, then it
> should only be considered of uncertain origin IF it actually bears some
> signs of captivity (feather wear, leg bands, unusual behavior, etc.). If
> it is not wildly unlikely, its remiges and retrices are not badly worn,
> it has been keeping company with other birds that may denote its
> origins, and its behavior is "natural", then the "default" attitude
> should be that it is most likely to be wild. 
> The barnie satisfies the last four criteria: no signs of feather wear or
> leg bands, associating with a huge flock of canadas (many of them
> lessers), greater white-fronts, snows, and a cackling goose or two. Also
> the barnie, like the rest of the geese in the flock is highly nervous
> about humans - very difficult to get closer than a few hundred yards.
> This is one where I would say that a captive origin is unlikely.
> FYI, Dick Veit wrote an interesting article for Bird Observer recently
> about the whole issue of how we should regard potential "escapes". I
> think that he makes a good deal of sense. 
> Hector Galbraith PhD
> Galbraith Environmental Sciences LLC
> 837 Camp Arden Rd., Dummerston, VT05301
> 802 258 4836 (phone)