Jerry Tangren wrote:

>Not to prolong a discussion, but a couple of comments...

But that's what tweeters is for, to allow us to prolong discussions from a
distance without having to use up telephone time or have the delay of
letters in the mail. I suppose the primary criterion for value would be a
reasonably high ratio of signal:noise.

>Problem in many discussions is what's high elevation to one person may
>not be to another. I never really regarded the C-bCs in the Blewett Pass
>area as being at high elevation. The whole area sort of runs together in my
>mind, and it's the more moist sites that I associate them with. The higher
>elevations are the ridge tops which are typically drier.

I don't see how you can get around calling 4,000', as at Blewett and Swauk
passes, "high elevation." To me, the lowland fauna and flora and habitats
of WA can be described as extending up to around 3,000', and the areas
>3,000' (or 1,000 m if one prefers, although that of course is higher) can
be called "montane." I have used that elevation as a break point in all my
thinking of lowland vs. montane in Washington, perhaps somewhat
arbitrarily, but it does correspond to some distribution patterns (it would
be different at other latitudes, obviously).

Indeed Chestnut-backs inhabit the wetter, denser forests, but these forests
are the ones at higher elevation in some of the mountain ranges, above the
ponderosa pine zone. It may even be that tree density is the key factor
rather than precipitation, as higher precip (which is at higher elevation
in drier mountain ranges) usually supports denser forests, but there may be
exceptions to this.

>The highest populations of C-bCs in Chelan Co. are in the Lake Wenatchee
>area where many sites are dominated by cedar and hemlock. I never thought
>of this area as high elevation.

Indeed not, it is the rather local east-side version of the west-side
forest that Chestnut-backs inhabit, but it isn't the same as the Engelmann
spruce/subalpine fir/mt. hemlock forests that Chestnut-backs inhabit at
higher elevations (it may well be continuous with them in some areas).

>>Mountains and Black-caps coexist wherever deciduous and riparian woodlands
>>abut conifer forests in eastern WA. I *am* surprised at Chestnut-backs in
>>Jerry's apple tree in Wenatchee; I would have thought that was way out of
>>their range, or only a destination of the occasional wandering bird in
>>winter. Is that a regular phenomenon, Jerry?
>
>>Dennis Paulson

>Regular? perhaps a more regular habit. C-bCs apparently wander quite a bit
>more than Mountain when you compare the relative numbers of individuals
>found in atypical habitats (Wenatchee backyards) versus the numbers found
>in the mountains just to the west.

Are Chestnut-backs in your yard every year? How many? Seasonality?
Putting some dates on this would be of interest to the people working on
the new Washington bird book, as I really think it's unusual. I ask for
details because my feelings have been that Mountain is more likely to
wander in winter than Chestnut-backed, so I looked in the last 5 years of
Christmas Bird Counts. Wenatchee and Ellensburg both had small numbers of
Mountains (I know there are ponderosa pines in Wenatchee, so they are
probably resident, but I think they occur in Ellensburg only in winter, as
is the case, occasionally, in the western WA lowlands). Yakima had none,
so they must not wander that far normally. But nary a Chestnut-backed in
any of them. Perhaps you live in a wetter area outside the Wenatchee CBC?

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