The first time I returned with the 100-400 to shoot the full body of the male, I was unsuccessful in getting a shot I liked. It appeared, and perched, but was usually partly obscured by branches, leaves, etc. which is not surprising considering the enormous length of the tail. So I came back after dawn the next morning, and this time was successful, with my favorite shot shown here. We were further fortunate that before entering the nest with the small Avocado for its chick, it turned and faced us. Many shutters clicked simultaneously!
One other comment on all of the Quetzal shots. If you have looked at the shooting specs, you'll see that basically these are full-flash shots. The tree containing the nest, and most of the surrounding area where they perched, were in fairly dense shade, throughout the day, even though skies were generally clear. There just wasn't an opportunity to shoot them with ambient light, so we had to settle for flash shots. I would really prefer to have shot ambient, with a little fill-flash perhaps, but that just wasn't possible in this location.