I am indebted to Neil Ellman of New Jersey, USA, for drawing my attention to this.  In his own words : the problem is this:  the stamp was issued in February, 1994, when dominica was a single species; but, during the same year, the 
American Ornithological Union (AOU) split the bird from its pacific coast counterpart, Pluvialis fulva, which became the Pacific Golden-plover.  The bird on the stamp is identified as dominica and the American Golden-plover, and it is further identified as a "Migratory Species of the Barbados."  HOWEVER, it appear to be fulva, based on the extended white stripe down the side.  This is understandable given the fact that the split occurred in the same year as the stamp was printed.
One can hardly blame the Barbados postal authorities for not knowing that the ornithologists would make a split, but in choosing a model for a stamp, they appeared to have chosen the subspecies (at the time) that could not possibly be
migratory through the Barbados.  What is identified as dominica and migratory through the area is, in fact, fulva and migratory only along the Pacific coast.

I have noticed in The Birds of the West Indies by Raffaele et al (1998) that fulva has occurred as a vagrant on Barbados where dominica occurs annually in large numbers.
 

Does anyone have any further views on this?