I could not rest until I learned what kind of bird this was. I asked my husband for help. After looking for bird images in the net, he said that the bird most closely resembled a Peregrine Falcon. Amazing. A Peregrine Falcon in our backyard? For comparison, here is an image from Wikipedia.
Late in the afternoon, when I had the chance to, I checked the place where I saw the bird to see what the black things in front of the bird might be. They turned out to be feathers which, judging from the shiny green specks, belonged to a Starling. There are Starlings in our area.
When I looked out of the kitchen window this morning, I saw this strange bird. It was the first time that I saw one like it here in our place or anywhere else. I was glad to have the camera nearby and took shots from the window. I wished I had a bigger zoom but I was happy enough to have this image (which I cropped to make the bird bigger). I went out to see it closer without the window between us, but birds, somehow, were attuned to my movements. They would fly with my smallest step, just as this one did. “What bird is this?” I wonder.