We have been monitoring the increase and spread of Bewick's Wrens in Idaho
and far eastern WA for the past 5 years or so. They have increased pretty
dramatically along the Snake R. in the Lewiston/Clarkston area and are
present in scattered locations throughout the Palouse area (Latah Co., ID
and Whitman Co., WA) They have also moved north as far as Lake Coeur d'
Alene, Idaho and Spokane, WA. In recent years there have also been more
reports from southern Idaho and at least 1 recent record from Missoula, MT.
Recently I have noticed more birds right here in Moscow although previously
they have seemed to preferred brushy draws, hedgerows, and riparian areas in
farmland and rural developments outside of town. I attribute this possibly
to an increasing population locally. (as a side note, Bewick's Wrens are
also increasing in Wallowa Co. in northeastern OR so they appear to be
spreading north and south from their core range along river corridors)

I think the increases in Bewick's Wrens we are seeing here are due to
habitat and climate changes (both anthropogenic causes which is what I
presume Dennis was eluding to). European Blackberry and other invasives in
the lower elevations may have encouraged the spread up along the Snake R.
but warmer winters have probably allowed them to move north into the Palouse
and beyond. Most of the areas mentioned have already been severly altered
for many years by large scale cultivation (on the Palouse) and grazing
(river bottoms, canyon grasslands, converted sage brush, etc.) however,
there is slow but steady develpment in the area resulting primarily in
conversion of farmland. This in time could create more suitable habitat for
this species.

Also on the watch list for expanding species in Lesser Goldfinch which is
coming from the south rather than the west.

thanks, Charles.

~~~~~~~~~~~~~~~~
Charles E. Swift
Moscow, ID, USA
charless at moscow.com
~~~~~~~~~~~~~~~~

~~~~~~~~~~~~~~~~
Charles E. Swift
Moscow, ID, USA
charless at moscow.com
~~~~~~~~~~~~~~~~