I am not sure if this is the right place to ask this question, but I guess that ornithology enthusiasts (or ornithologists) will have the best knowledge about it.
I am wondering if there is a website which would identify birds by their looks. For example, I would specify that the bird is similar to a sparrow in size (just a little bigger), it has a gray back and yellow-ish-orange-ish belly and it would tell me the exact species.
Does such a website exist?