One night Thoreau was startled by a honking goose, and “heard the sound of their wings like a tempest in the woods as they flew low over my house.” A cat-owl responded “with the most harsh and tremendous voice I ever heard from any inhabitant of the woods… as if determined to expose and disgrace this intruder from Hudson’s Bay by exhibiting a greater compass and volume of voice in a native, and boo-hoo him out of Concord horizon.”
Goose and owl hollered back and forth, and Henry said, “It was one of the most thrilling discords I ever heard. And yet, if you had a discriminating ear, there were in it the elements of a concord such as these plains never saw nor heard.”
Along with some Thoreauvian wordplay, this is another one of those tantalizing remarks that Henry throws off without further explanation. In the cacophony of the rival bird calls he discerns an order lurking behind it.
A “cat-owl,” by the way, is another name for the tawny owl or brown owl. It is this…
…and not this:
For your amusement, more fake cat-owls are here.
(About “A Year in Walden”)