Roger, I agree with you that the lab's view of the world is apparently of
forests with no undergrowth. When my husband and I did spot a tanager
last year on the second site visit, when we were to determine nesting, we
tried to follow the bird through our typical salal & etc. understorey
with results you could predict. Husband Steven photographed the area to
show the folks at the Cornell Lab. of O. what it looks like here.

We definitely are novices, yet we felt somewhat prepared to do the study;
the lab does give aids to identification. They provide a booklet with
pictures of male and female tanagers and cowbirds (I think), but no
pictures of the nestlings of each--that would have been helpful. In
addition, very helpful was the cassette tape the lab provided, giving not
only tanager calls and songs, but also similar songs so that we could
really listen and try to distinguish among the species. I think the tape
was very well done and organized. Our tape was for the Western tanager
only, of course, not other tanager species. I know that, even with these
aids, people will still make mistakes. However, I think the lab does
what it can, given what it is asking and to whom (basically everybody),
to prepare volunteers as well as possible.
I hope this note answers at least some of your questions. Thank you for
your comments. --Anna Coles, Seattle acoles at u.washington.edu