American Tree Sparrow and Chipping Sparrow

I haven't had much experience seeing these two species side-by-side. Traditionally, the American Tree Sparrow is here in the winter, and the Chipping Sparrow is here in the summer. Initially, I have found myself having to do double-takes to confirm which visitor is at my feeder. Three CHSP and two ATSP have been hanging out here for about a week.  It was a challenge to get them both in one shot, given their activity and focus depth.  To make it worse, the ATSP bullied the CHSP off the feeders.

Side-by-side, the ATSP is much larger. Even though the ATSP is on the back of the feeder in the top picture, it looks larger than the CHSP.

The ATSP has a bold gray feathers for its 'eyebrow', that almost projects higher than the crown. Plus, the red is more bold on the ATSP.

The 'thumb print' on the breast is sometimes clear on the ATSP. The CHSP looks pretty nondescript to me this time of year.

The bi-colored bill on the ATSP is a sure distinction, if you get a good enough look. The above picture shows this best.