Regarding separating the east-side and plains races of Spotted Towhee against
our usual coastal race, Oregonus: Here are the difference I observed on the
bird in question while birding the skagit game range on sunday:
1. the bird was an adult male
2. quite heavy scapular spotting, as opposed to a typical close bird close
by, which lacked much of the same heavy spotting.
3. paler undertail coverts. contrasting with the rufous sides, more so than
Oregonus.
4. Large white spots on the underside of the tail. maybe twice as large as
Oregonus.

One can argue that you should just leave these birds unidentified to race in
the field, as there is alot of variation within the certain types and also
integrades between subspeces. But with typical individuals of each race, as
the bird seen in Skagit, it was quite easy to place to the east-side variety.


Good references to refer to are Peter Pyle's Identification Guide to North
American Birds. Also the National Geographic guide, 3rd edition shows the
races quite well, including undertail views.


Ryan Shaw
Lacey, WA
RTShaw80 at aol.com
http://hometown.aol.com//rtshaw80/index.html

I asked Steve Mlodinow to elaborate on what I had written: the subspecies of
SPTO:

Yes, with subspecies vs. species, intermediates exist. One could argue that
you shouldn't ID flickers, juncos, Yellow-rumped Warblers because there are
integrades. But people do that all of the time. However, coastal and interior
Spotted Towhees are fairly well recognized as being separable a fair amount
of the time. I have looked at hundreds if not thousands of towhees in e and w
Washington over the last 3 years as well as at specimens at the Burke.
Largely, the interior and coastal birds are separable.

Scapular spotting: Generally heavier on interior races, reduced on coastal
race. Males are more spotted than females in my experience, and some male
coastal birds can look fairly heavily spotted.

Undertail coverts: Contrastingly paler than flanks on interior birds and
little or no contrast on coastal birds. Have seen the occasional female
coastal bird with paler undertail coverts.

Undertail white: 12-25 mm on R6 in Oregonus (which is the coastal race) and
22-42 mm in inland races.

After looking at hundreds of these birds, and after travelling back and forth
from eastside to westside, the vast majority of Spotted Towhees are EASILY
assignable to one group or the other. Yes, there are some intermediate birds,
and I leave these unidentified (as I would some juncos and many flickers). It
does NOT mean that typical birds cannot be separated.