Dear Bird Correspondent

Dear Bird Correspondent, I had a good close look at our resident bird today and am no longer convinced that it is a Carolina wren. First, it definitely DOES NOT have the distinctive white stripe over its eye. Second, our bird has alternating bands of dark and light feathers along its chest and belly - almost like stripes - that I have not seen in any pictures of Carolina wrens. Third, its tail, while somewhat resembling the tail of a Carolina wren, does not stick up. It is parallel to the ground. Fourth, the bird appears to be larger than an average Carolina wren. Fifth, our bird seems to be (on its back and head and wings) a more solid and rustier brown. The bird does share with the Carolina wren a long, pointed beak (with which, as I have just observed, it likes to crack open acorns and eat them) and a spherical body type. What do we have, Dear Bird Correspondent? A mutant Carolina wren?