Hi all:
I thought that I'd respond to Jeff's query about juncoes, as I've spent no
little time studying them in various parts of Colorado.
First off, I agree with Jeff in that Peter Pyle's treatment of the Dark-eyed
Junco complex is better than the A.O.U.'s, but that's because the latter's is
over 50 years out of date. Secondly, and very importantly, I (and others)
firmly believe that Pink-sided Junco (PSJU) has received very short shrift when
some have pondered upon the complex. In my experience, Pink-sided is MUCH more
similar to White-winged Junco (WWJU) than it is to Oregon. It sounds like a
WWJU (whose contact calls differ noticeably from those of the rest of the
complex), it's pale gray like a WWJU, it has gobs of white in the tail like a
WWJU, it mostly lacks brown coloration as immatures like a WWJU, and it's big
like a WWJU. It's just not an Oregon Junco! I suspect that if any splitting
of Dark-eyed Junco comes along in the future, we will see WWJU and PSJU being
split (possibly together as one species) from the Oregon (ORJU)/Slate-colored
(SCJU) group. (What happens to the red-backed juncoes -- Gray-headed,
Red-backed, and Yellow-eyed -- in such a situation I have no idea.)
Finally as far as CO occurrence, at least two subspcies of ORJU occur: the
common and widespread shufeldti and a rarer from (that is mostly restricted in
CO to the West Slope) that I think is thurberi. The difference between the two
is often striking, particularly in adult males, with the latter having the head
black and strongly contrasting with the rufescent back, unlike the much dingier
and paler shufeldti (including montanus). Females of shufeldti can be confused
with PSJU, but note that ORJU typically has the least amount of white in the
tail of all junco forms in the ABA area, while PSJU has nearly as much as WWJU.
Size, too, can be of assistance in separating difficult individuals.
I have not found any reliable treatment of junco taxonomy and/or ID on the web,
probably because only the interior West has such abundance of syntopic forms
and, we're not coastal so we don't really matter.
Sincerely,
Tony Leukering
Villas, NJ
Topic: FOS 'oregon' Junco - Teller County
"Jeff J Jones" <[email protected]> Oct 13 04:45PM -0600 ^
My FOS Oregon Dark-eyed Junco (shufeldti?) appeared today at my feeders.
In addition, also my 5th appearance of a Blue Jay in 22 years! Cassin's
Finches, and gray-headed and pink-sided races of Juncos as well.
Concerning Juncos - I would like to open a conversation on this topic as per
the races occurring in Colorado.
I think there is not complete agreement upon the systematics of this bird;
e.g. the number of recognized races. I believe that Pyle and the AOU
disagree on specifics here among the Oregon and Pink-sided groups.
Unfortunate because I feel that Pyle gives the most useful descriptions for
the races.
Pyle lists 5 subspecies of the Oregon group (oreganus, simillimus, thurberi,
pinosus and shufeldti) and 1 subspecies of the Pink-sided group (mearnsi).
While AOU lists 8 subspecies for the Oregon group, of which they consider
Pyle's pink-sided race to be a part of (oreganus, shufeldti [lumping Pyle's
simillimus in here I think], montanus, thurberi, pinosus, pontilis,
townsendi and mearnsi).
Using Pyle, my understanding is that Oregon shufeldti, Pink-sided mearnsi,
Gray-headed caniceps, White-winged aikeni, and Slate-colored cismontanus and
hyemalis can occur in Colorado. With the only potential difficult
identification being between the two races of slate-colored; with
cismontanus showing a hooded effect wherein hyemalis does not. I think there
could also be some issues between shufeldti and mearnsi with some variation
between females. Also, confusion with some slate-colored showing distinct
white wing bars confusing it with aikeni - but more easily differentiated
using other diagnostic features, e.g. white rectrices and bill color.
Using AOU, shufeldti and montanus both can occur in Colorado I think - but I
am not sure how to separate them in the field.
Do I basically have this information correct above?
Can anyone add to this?
Is there a resource on the web with some of this info already? A Google
search failed find it.
I am recommending a response to the group as opposed to individually to me
in order to spark group discussion on this please to drive towards a
consensus on this topic.
Thanks.
Jeff J Jones
( <mailto:[email protected]>; [email protected])
Teller County - 8500' - Montane Woodlands
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