Whether or not the commonly used bird watching term “giss” actually has its origins in an old British military acronym for General Impression Size and Shape (GISS) is a question perhaps best left to the etymologists. However regardless of from whence it originated, it is a most handy tool to have in one’s field craft kit.
The basic concept of giss is really quite simple. With only a relatively quick look at something or someone, one can have at least a half-reasonable idea of what or who it is from the overall size, shape, and other basic significant characteristics. You might not be able to describe all the “field marks” of, say, your uncle Fred, but you can pick him out of a crowd instantly by knowing him to be a portly, middle-aged man of medium height who sports a long red beard and walks with a limp. The principle is the same with birds – in fact, most of us do it unconsciously when first sighting any bird, right down to the most basic level of determining that a creature seen is in fact a bird rather than a squirrel, a garden gnome, or your uncle Fred.
Yet while giss is often discussed in essays about bird watching field craft, I have recently been wondering if there might be such a thing as reverse giss. This would be applicable to all those situations when you see something or someone you know perfectly well but fail to be able to identify correctly as it, he, or she is observed in an unfamiliar location. This has happened to me many times with the most familiar of birds; I have not been able to immediately identify them simply because I saw them outside of the areas in which I most commonly see them.
The floor is now open for comment or rebuttal.
