Brenda Senturia wrote:

>>Tweeters-
>>I have been hiking alot the past few weeks at the 3500 - 5000 ft.
>elevations
>>on the east side of the Cascades. I have been trying to figure out why I
>>sometimes see Mountain Chicadees and sometimes Chestnut-backed Chicadees.
>>While the Mtn. tend to occur at higher elevations and in drier habitats,
>>I am often surprised by Chestnut-backeds where I don't expect them.

And Jerry Tangren wrote:

>That almost seems the rule with C-bCs. They can occur almost anywhere. Even
>in the apple tree in our Wenatchee backyard.
>
>However, they seem to be most likely, as you suggest, in the more moist,
>low level forests. The most dependable sites are those dominated by
>west-side kinds of trees, hemlock and cedar. In other words, they aren't
>real common in predominatly pine habitats.

Actually, I associate Chestnut-backs in Washington with two habitats: (1)
the low-altitude wet forests of the west side and the very northeastern
corner of the state, which are very similar (lots of west-side plants &
animals in that area); and (2) relatively high-altitude wet conifer forests
in all the mountain ranges of the state. Where wet forests are continuous
with high-elevation forests, as in western WA generally, the range is
continuous, but in the Blue and Wenatchee mountains and Okanogan Highlands,
CBCHs are found only at higher elevations, essentially isolated as are many
other high-mountain birds. They are typically in fir, hemlock, and spruce
rather than pine forests in the mountains.

On the average, CBCHs are found in wetter, denser conifer stands in the
mountains, Mountain Chickadees in drier, more open stands, but they
certainly occur together in many areas. Both came to pygmy-owl calls at
several sites at 4-5,000' above Swauk Pass in the Wenatchee Mountains last
week.

Mountains and Boreals seem to overlap completely in the northern part of
the state, but I don't think I've ever found Chestnut-backed and Boreal
together. Perhaps Chestnut-backed aren't so common in the high-elevation
spruce and lodgepole pine forests that Boreal frequents. Any comment,
Andy?

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, 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