by Lisa Milewski
According to The Cornell Lab, All About Birds, many birds, especially Blue Jays and Cardinals, molt in late summer and fall. It grows and replaces feathers gradually but occasionally a bird may lose all the feathers on its head at once, particularly Blue Jays, in which molt of the feathers of the head “capital tract” in synchrony. This usually occurs in juveniles undergoing their first prebasic molt.
My apologies for somewhat blurry photos since they were taken through the window to not scare off the bird.
The last one is filling in a bit, but don’t worry! They will all be beautiful again eventually.
Nature Along the El Camino Real 