>On the discussion of boreal chickadees, why don't we encounter the
>phenomena of boreal chickadee invasions such as occur in eastern North
>America? Is the potential source of birds too small, the ecology of
>western forests different, or has the notion of invasions been
>overblown?
>
>Jerry Tangren

Jerry posed an interesting question, to which I'd like to add what I
consider an even more interesting one--why don't we have irruptions of
BLACK-CAPPED chickadees, which are well-known in the east? This bird is
very common, and we'd surely know of such movements. Mountain chickadees
move downslope a bit in winter, appearing from time to time in western WA,
but I haven't heard of black-capped movements either E of W of the
Cascades. Anybody ever seen one?

Of course the forests in which black-capped chickadees live here are indeed
rather different from the deciduous forests of the Northeast. Black-capped
here is not the climax-forest chickadee, as it is in the East, and its
populations may be a lot smaller and not subject to the same cycles that
might occur in the extensive eastern forests.

By the way, for a great book, read Susan Smith's "The Black-capped Chickadee."

Dennis Paulson