Paul, just a few comments on your interesting account.

First, I wouldn't have been surprised if the male has a higher voice, as he
is a little smaller than the female. There is such a relationship.
However, a quick perusal of Johnsgard's owl book found only brief mention
that in both Eastern Screech-Owl and Great Horned Owl the male's voice is
lower-pitched; nothing about Western Screech. Maybe the higher-pitched
notes you hear are the female calling the male? Maybe you can figure it
out.

Second, you're right about the female incubating and the male feeding her.

Third, the passerines have more to fear from the Barred than from the
Screech. The former eat just about anything, the Screech primarily
earthworms, insects, and some rodents. And I think Barred Owls are more
likely to hunt when there is still a little light, when tweety birds are
out and about.

Dennis Paulson, Director phone: (206) 756-3798
Slater Museum of Natural History fax: (206) 756-3352
University of Puget Sound e-mail: dpaulson at ups.edu
Tacoma, WA 98416