I had a visitor to my backyard the other day that was a bit of a challenge for me and in attempting to identify her, I did something I have never done before. But more on that below.
Remember, when you come across an unfamiliar bird, do not reach for your field guide first. The bird is unlikely to sit still for the comparison process, and you will likely forget what the bird really looked like before you find it. Instead, sketch or make mental notes of key identification features and get a picture if possible. These are some of the most important things to make a note of:
The tail coverts are dark, almost slate colored. Underneath is white. In fact, when I first looked at this bird, all I really saw was her tail and my first thought was, “The juncos are back?” My second thought, as i moved to a better window was, “What on earth is a junco doing on the platform feeder?” I have never even seen them even as high as the ground feeder unless the snow is deep. But the view from the side made it clear that she was not a junco. The wing coverts were dark as well, with white feathers underneath. (The coverts are the feathers which cover the quills.)
I really could only see her from this profile, but her breast is white with notable streaking. The streaks are dark and form solid lines. This was new for me, because it reminded me more of the female rose-breasted grosbeak we had earlier in the year. This bird was nowhere near that size, but the house finches I have seen so far do not have such clearly defined lines on their breasts.
She is about the size of a goldfinch. At least that was my first impression. I had no other birds to compare her with, but she seemed on the small side.
Large and conical. The upper mandible is darker than the lower mandible. The ratio between the beak size and head size seemed more like that of a grosbeak. But all the grosbeaks I know of are closer to a cardinal in size rather than a goldfinch.
Not particularly shy. I moved around the window a bit, and she was undisturbed. I opened the back door, and she did not fly off until I actually went out the door (which is about 20 feet from the feeding station). She was picking sunflower seeds out of a mixture of millet, cracked corn and sunflower seed.
Dark and solid in color. No noticeable eye markings, but these may have been masked by the apparent eye disease.
At first, I thought the eye was missing, but closer examination shows a possible infection. House finches are somewhat susceptible to conjucntivitis, and this appears to be the problem here.
Because of the darker coloration and especially because of the beak size, I was not completely sure what kind of bird it was. So I took another step in the identification process. After comparing the photo to the bird guide and several pictures on the Internet, I consulted with more experienced birders. There may generally be found at a wildlife store or your local nature center. I posted mine at birdforum, asking what it was.
There, the consesnsus was that it is indeed a house finch, probably with conjunctivitis. The beak is a little large for the species, but there can be considerable variation among individuals in any species.