How Bird Appearance Can Be Deceiving

One of the challenges in understanding the color patterns of birds is that we only see the tips of their feathers and feathers are flexible. This means that the longer feathers on the body can move a lot relative to their neighbors, and the color patterns formed by the tips of the feathers can change depending on where the feathers go.

We often see it in the striated patterns on the chest and flanks of many species. These feathers are particularly long and flexible, and the dark streaks on the tips of the feathers end up forming irregular wavy lines rather than smooth, even streaks.

The shorter, more rigid feathers – for example, around the face and on the wings – move much less and form much more consistent and reliable patterns, which is one of the reasons why we end up focusing on these feathers for identification.

Another aspect of this is that the head feathers move with the head, while the “chest” feathers (which actually grow from the front of the neck) mostly stay with the body. The upper breast feathers (of the upper neck) turn a little when the head turns, but their length and flexibility tends to keep the tips of the feathers aligned with the lower body feathers and the feathers of the lower part of the body. Chest. does not spin at all.

I saw this in action recently while watching a blue jay, and made the sketches above to show the changes as the bird’s head turned. The dark frame around a blue jay’s face and throat is an unusual plumage pattern that includes fairly inflexible head feathers on the back of the cheek and fairly flexible breast feathers.

Notice how the dark frame behind the cheeks moves with the head and does not change shape as the head rotates, a narrow ring of feathers between the head and the body partially rotates with the head, and most of the dark headband remains aligned with the body .