The minutes of peaceful feeding usually end with the noisy arrival of a family of Blue Jays. They are molting in late August and every year one or two sorry-looking individuals show up bald - with few feathers, or may be just a stubble on their heads. Fortunately that's only a temporary state lasting about two weeks until the feathers have regrown.
Although adult, they often look immature because their large eyes are more characteristic of chicks:
In a study published in the journal Nature on 5/27/12 examining this curious fact the authors conclude that
"We have provided a powerful new example of how heterochronic changes, paedomorphic" (retaining juvenile characteristics) "and peramorphic" (early development of adult characteristics) "were crucial in the origin and evolution of birds. We further demonstrate that these changes were driven by an extreme degree of elaboration in vision-associated areas of the brain that parallels the olfactory elaboration of mammals, and possibly by the evolution of the face into a precision grasping mechanism as the hands were co-opted for flight."
There is a very readable illustrated summary of the study in ScienceDaily: Evolution of Birds Is Result of a Drastic Change in How Dinosaurs Developed