Seasoned birders only need a quick glance at the bird pictured above and will instantly recognize it for a first-fall White-crowned Sparrow. Identifying birds in this manner becomes possible by spending hundreds of hours in the field, from one migration to the next. No longer relying upon a methodology of taking serial steps and deduction via comparing similar looking species pictured in a field guide, an experienced birder's mere glimpse of a species is often enough to make an instant identification. In astonishment, and perhaps somewhat skeptically, a new birder might ask, "How do you know? It's crown isn't even white and looks just like an American Tree Sparrow."
Sometimes it's less about particular plumage colors and more about size, shape, behavior, habitat, and seasonal timing. Like me, I've heard other experienced birders say it can be challenging to compose the precise words that conveys a meaningful ID description to a novice. I don't use a field guide when I'm birding alone and haven't for years. Since I don't run through the descriptive words for a given species in my mind, I'm probably out of practice when asked to do so. "Um, it's a, well, just look at it! It's a White-crowned! How about that crest, eh?"
It's a more holistic process. I think it comes from our innate ability to recognize patterns. After all, there was a time in the history of our species when being able to recognize forms in nature was pretty darn important to our survival. It remains with us. Perhaps this helps explain our fascination with birds, other animals, and plants when going for a hike through the woods or prairie. It's obvious to me that the human spirit thrives best when immersed in nature's realm. Being able to identify many kinds of birds isn't a contest. For me, it's an assurance that renders a particular sensation stemming from a time when we were more meaningfully connected with nature.
White-crowned Sparrow © 2011 Mike McDowell