Mary Ann Chapman wrote,
> You probably know this, but both occur in Texas and are fairly common
within their ranges, or at least they were when I lived there up through
the mid-80s. At that time, there was a distinct dividing line between the
two that ran right down the edge of the Edwards Plateau. It was so
distinct that it ran down the west side of Austin, and you would see tufted
and no black-crested east of the line. West of the line, you would see
black-crested and not a single tufted.

That's fascinating, and if it's still true in 2005 it means that the populations are really allopatric and that their species status can't be determined by the criterion of interbreeding because they never meet. So they really ought to be considered semispecies that form a superspecies, and the AOU listing them as full species is just an arbitrary choice. Next edition of the AOU Checklist, they could be lumped again. That's why I think it's silly for birders to have their potential life lists yanked up and down, and that there ought to be a stable list for birders to follow (my article in Birding about a year ago), but most folks don't seem to agree.

Burt Guttman
The Evergreen State College
Olympia, WA 98505 guttmanb at evergreen.edu
Home: 7334 Holmes Island Road S. E., Olympia, 98503