The flicker's exhortation to seeing and hearing is a theme in the works of Gary Snyder, who likens its cry to the zen master's exclamation, "This! This! This!" This is a reminder to see things as they really are, independent of the images and notions we form about them. Because "Whimsy Walks" has to do with ways we can project our imaginations into the things we encounter, this may seem like a contradictory point to be bringing up. However, I think it's possible to maintain a dual consciousness, acknowledging that other beings have their own realities, while entertaining our own little fantasies about them--as long as we remain respectful. After all, who is to know whether some of our imaginings engage reality on another level?
Because flickers are Michigan's most common woodpecker and have such distinctive markings, they were among the first birds I learned to identify, beyond the obvious robins, cardinals, jays, et al. (In those days I was more into my seeing function, as the only bird call I ever noticed was the mourning dove's; I didn't start paying attention to sounds until I was in my 40s.) Nowadays, the recognition of different birds revives memories of my first sightings, which in the case of flickers, was on a walk in the autumn-yellow woods. Also, there is something about the way a flicker flashes his big white spot during a sudden take-off that can be just a little bit startling--not unlike the flash of insight.
p.s., the flicker pic is by F.C. Hennessey, circa 1919.