A raven flies to its roost at dusk, wingbeats audible between the calls. Just before this flight, the bird was amusing itself with half a dozen others of its kind by harassing a sluggard-winged eagle. The ravens wove and swooped; the eagle flopped its great wings, finally passing out of sight on the horizon.

I think the squealing call at the end is a younger raven, greeting its homeward-bound parent.

Spectrogram. Time moves left to right, pitch increases along the vertical. “Stacked” lines are harmonics.

Night came and with it a frost.

I lingered and was rewarded by the sounds of Northern Saw-whet Owls. These tiny owls are common in dense forests of Canada and the Western US, especially forests with rotten trees to supply nesting holes. In the winter, some birds move south, so Saw-whets can be found all the way to Florida in the right season. The bird gets its name from the supposed resemblance between its repeated whistled call and the action of whetting a saw. The analogy is stretched, unless your saw comes with a flute.

The owls were a distance away, so the following recording has some lower and higher sounds filtered out to make the call come through more clearly.