There's an interesting post (with tons of golden comments) over at the Drinking Bird, to which this post is some sort of follow-up, or rather the results of a few follies ("thoughts" - remember?) of mine that were sparked by the post and its comments.
Am I a GISS birder or am I not?
First, I think it is necessary to define GISS. It means General Impression of Size and Shape, and if someone identifies a bird by GISS, they only go for the bird's appearance, not really its field marks.
Now, of course I can see that one would be able to identify birds of obvious size and shape by these traits alone, say a Limpkin or a Great Horned Owl or an American Robin where other Turdus - thrushes don't occur, but I have a nagging feeling that most observations we do "from the hip" and thus attribute to GISS-identification actually are not GISS after all but something completely different.
An example should do nicely to get my point across:
We spot movement on the ground below a barren winter bush, raise our binoculars and immediately identify the bird as a White-throated Sparrow.
Asked a few moments later by what field marks we identify it, we just respond with a shrug of our shoulders, stating that it was just obvious the moment we looked at it.
Was that identification by GISS?
I think not.
I think this was just an extremely fast conversation between our eyes and our brain along the following lines:
Eyes: there's movement of a small brown bird on the ground.
Brain: check the back, is it patterned?
Eyes: yes, it is patterned in stripes and spots.
Brain: Sparrow! Check the head pattern.
Eyes: black and white stripes.
Brain: White-crowned or White-throated. Check throat.
Eyes: throat is white.
Brain: It's a White-throated. Mouth: YAWN
Of course, the last bit that involves the mouth would be completely different if our little scene would take place inside a visiting birder from overseas. Face it, North America: the White-throated Sparrow is amongst your finest birds, however common it may be.
This conversation can take as little as a fraction of a second, somewhat depending on our activities the night before, and we may therefore be unaware of it.
My conclusion is that most identifications that are done real quick and are often attributed to GISS are indeed very fast conclusions drawn from checking the precise field marks that are necessary by actively scanning the bird's features. And this means they are made solely because of our knowledge and experience, which is why beginning birders usually suck at this until they've done a few years worth of birding.
Knowing immediately into what broad group a bird belongs and then knowing which parts of the bird to check for which field marks has got nothing to do with GISS identification, it is just plain old bird ID gone ultrasound.
Another difference between a more experienced birder and a novice that is somewhat related to GISS-ascribed identification is the ability to focus our concentration on an object we see, the ability to take a mental snap-shot.
Show two test persons of varying birding experience a bird for just a second, a bird neither one has ever seen.
The more experienced will probably manage a reasonable description.
The novice will just be overwhelmed by the bird's many features and later have no idea whatsoever when asked to sketch it.
This ability is also vital when identifying birds very quickly: The expert's assessment of "Catharus, weak reddish spots on breast" (this will again not take longer than a fraction of a second or so) is more likely to lead to Veery than the novice's "oh my gosh! a brown bird, wait (minors may potentially read this), where did it go?" even if we give the latter birder an extra second.
Now, if that novice birder would stand besides the expert, having just seen the same bird hopping by so quickly, hearing him say "Veery" immediately, and then ask him how and why s/he knew so quickly, the expert's answer would probably be "You know, just the whole thing, it was obvious" and we would call that GISS ID. As in the first example, the point is that an identification made real fast (in the first example it took us only a split-second, in the second example the bird gave us only a split-second) is often attributed to GISS- Identification.
And as in the first example, I think it isn't.
So, here's my assessment: the fact that expert birders are able to identify birds amazingly quickly whereas beginners struggle is due to these two abilities:
a) they know immediately which areas of the bird to check for which field marks
b) they can make a mental snap-shot of a bird
Neither of these has anything to do with the assessment of the bird's general impression of size and shape, it is based on having learned the area's species potential by heart and having practised your eyes/brain coordination.
Having said that, I will now get back to the initial question of this post: am I a GISS birder or not?
Well, for the most part I am not.
I am someone who has spent prolonged periods of time in various places of the globe and within these regions, I simply have learned the species over time, know what they look like, know what to expect and what features to focus on. Within these regions, I will identify the very vast majority of the birds I see within less than a second. However, this to me in not bird ID by GISS or intuition, it is just bird ID routine.
GISS does play a certain role though:
There are a few groups of birds where the general impression of size and shape is important, and that is birds seen mostly over long distances.
I can usually identify flying raptors by their flight style and very general proportions.
I can usually identify jaegers and jaegermeisters at very long range by their impression of size and flight style - which I find easier than identifying them at short range - but this is usually where the identification bit of the GISS technique ends.
The most important aspect of GISS however is this:
In my approach to bird identification, GISS is used mostly not to tell me what a bird is but to tell me what it is not!
A mismatch between the general impression of size and shape and the features I see is what gets my adrenaline flowing as it means I am seeing something I should not be seeing, so it's got to be something special.
Whenever this happens, I start making notes or hopefully taking pictures to allow for a thorough analysis of the observation. Usually, a bird whose GISS is okay but whose plumage does not correspond will be an aberrant familiar bird, like a leucistic or worn or whatever shabby individual. Sometimes however, it can end up being quite a special bird (although this one was caged).
To conclude, I would say that I am mostly a birder with a significant amount of routine on his familiar stompin' grounds who uses GISS mostly to seek the unusual amongst the usual, and not to really identify a bird.
This should make the rarity committees rather happy.