Totally Random: Pretty Little Bird Outside My Office Window

For the past couple of weeks, the little bird below has been randomly tapping at my 2nd floor office window. The bird's feathers seem quite fitting for fall, with its shades of red, rust and brown and overall, it's such a pretty little thing. I'm not sure why all the tapping, but he (or she) seems quite persistent. Anyway, if anyone knows what kind of bird this is, I'd love to know. You can see more pictures by clicking here.