(Bellingham, WA, USA)
I was able to get a good close look at it's head because it flew into a large glass window and lay on the outside sill for almost 10 minutes. If I had known it would be there that long, I would have gotten out my camera.
Most distinguishing and definite marking were stripes (front to back)on the crown: center deep gold stripe - a definite stripe with distinct straight line. On both sides of this center stripe were black stripes. All three strips were equal in width. and then a white stripe next to the black...guess the white stripe (which was not as distinctly delineated as the gold and black stripes)would be termed eyebrow stripes.
The beak was short and thin... it would have appeared tiny if it had been any any larger bird. Probably no more than a sixteenth of an inch long.
The bird was no more than 5-6 inches beak to end of tail. Breast feathers gray and back and wings were dull brown, with a bit of a greenish tint
Soon after the sound of the bird flying into the window on the back of the house, near where I was seated, I heard the same sound on a different window on the front of the house. I found another of this same species lying on the front porch, but since it was clearly recovering from the shock of flying into the large glass window, I did not want to open the front door and startle it. So I went back to the window to get closer look at the one on the window sill.
I really could only see the breast of the one on the sill and would have thought it was a bird with gray feathers had I not seen the one on the front porch who was lying on its belly and I could only see the back and wings. But on each of the birds the clearly dominant marking was the crown of the head! It was exactly the same on each of them.
I have watched birds closely for many years and have never seen this bird before -- here in Bellingham Washginton or in other states we have lived (Maryland, Missouri, Georgia, California, New York) The closest thing I can find in my bird ID books is a Kinglet, but it is not exactly what I saw.... Do you have any ideas?
It certainly sounds like a Golden-crowned Kinglet. There is also a Golden-crowned Sparrow.