Colorado Birds - The Hungry Bird: Sapsucking Woodpeckers Barn Owl Nest Box Swap In the Scope: Subspecies in Colorado - Colorado Field Ornithologists
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
Vol. 51 No. 3 Summer 2017
Colorado Birds
The Colorado Field Ornithologists’ Quarterly
The Hungry Bird: Sapsucking Woodpeckers
Barn Owl Nest Box Swap
In the Scope: Subspecies in Colorado
Colorado Field Ornithologists
PO Box 929, Indian Hills, Colorado 80454
cfobirds.org
Colorado Birds (USPS 0446-190) (ISSN 1094-0030) is published quarterly by the Col-
orado Field Ornithologists, P.O. Box 929, Indian Hills, CO 80454. Subscriptions are
obtained through annual membership dues. Nonprofit postage paid at Louisville, CO.
POSTMASTER: Send address changes to Colorado Birds, P.O. Box 929, Indian Hills,
CO 80454.
Officers and Directors of Colorado Field Ornithologists: Dates indicate end of cur-
rent term. An asterisk indicates eligibility for re-election. Terms expire at the annual
convention.
Officers: President: David Gillilan, Littleton, 2019*, president@cobirds.org; Vice Pres-
ident: Christy Carello, Golden, 2019*, vicepresident@cobirds.org; Secretary: Chris Ow-
ens, Longmont, 2019, secretary@cobirds.org; Treasurer: Michael Kiessig, Indian Hills,
2019*, treasurer@cobirds.org
Directors: Amber Carver, Littleton, 2018*; Gloria Nikolai, Colorado Springs, 2018*;
Christian Nunes, Longmont, 2019; Christy Payne, Wheat Ridge, 2020*; Jason St.
Pierre, Durango, 2019*
Colorado Bird Records Committee: Dates indicate end of current term. An asterisk
indicates eligibility to serve another term. Terms expire 12/31.
Chair: Mark Peterson, Colorado Springs, 2018*, mpeterson33@yahoo.com
Committee Members: Lisa Edwards, Secretary; Peter Gent, Boulder, 2017*; Tony Leu-
kering, Largo, Florida, 2018; Dan Maynard, Denver, 2017*; Kathy Mihm Dunning, Den-
ver, 2018*; Christian Nunes, Longmont, 2019*; Steven Mlodinow, Longmont, 2019*
Immediate Past President: Doug Faulkner
Colorado Birds Quarterly:
Editor: Scott W. Gillihan, editor@cobirds.org
Staff: Christy Carello, science editor, vicepresident@cobirds.org; Debbie Marshall, de-
sign and layout, marshallpublish@gmail.com
Annual Membership Dues (renewable quarterly): General $25; Youth (under 18)
$12; Institution $30. Membership dues entitle members to a subscription to Colorado
Birds, which is published quarterly. Back issues/extra copies may be ordered for $7.50.
Send requests for extra copies/back issues, change of address and membership renewals to
membership@cobirds.org. Contributions are tax deductible to the extent allowed by law.
COPYRIGHT © 2017 by Colorado Field Ornithologists. Reproduction of articles is permitted only
under consent from the publisher. Works by U.S. and Canadian governments are not copyrighted.
126 Colorado Birds Summer 2017 Vol. 51 No. 3
The Colorado Field Ornithologists’ Quarterly Vol. 51 No. 3 Summer 2017
PRESIDENT’S MESSAGE........................................ 128
David Gillilan
CFO BOARD MEETING MINUTES.......................... 130
Chris Owens
CORRECTION: BIRDS AT LAIR O' THE BEAR
PARK OVER THE LAST DECADE........................... 133
Scott W. Gillihan
SUMMER OBSERVATIONS OF PACIFIC
WRENS LIKELY BREEDING IN COLORADO.......... 134
Mike Britten, Jeff Connor, and Kurt Fristrup
NEWS FROM THE FIELD: WINTER 2016–2017..... 142
David Dowell
IN THE SCOPE: SELECTED BIRD SUBSPECIES
OF INTEREST IN COLORADO: PART 1................... 154
Tony Leukering and Steven G. Mlodinow
THE HUNGRY BIRD.............................................. 170
Dave Leatherman
EXCHANGING AN ACTIVE BARN OWL
Purple NEST BOX.............................................................. 174
Sandpiper, Scott Rashid
1st Colorado
record, Iron
Spring Creek
near where it
enters Dillon
Reservoir,
Summit Coun-
ty, 19 Dec 16.
Photo by Bill
Maynard
PRESIDENT’S MESSAGE
Like many incoming Colorado Field Ornithologist presidents be-
fore me, my first President’s Message for our flagship journal Colorado
Birds is being written shortly after the conclusion of another suc-
cessful annual convention and membership meeting, this one having
taken place in Steamboat Springs. I was first inspired to join CFO by
the prospect of attending an upcoming convention (Trinidad, 2012),
which may very well be how many of you first became members of
CFO as well. CFO and conventions have been closely entwined from
the start; CFO was created in 1965 as a
statewide entity to sponsor annual con-
ventions (Colorado Birds, Vol. 46:3, July
2012).
At the conclusion of my first con-
vention in Trinidad, I pondered which I
had enjoyed more; all the birds I saw, or
getting to know so many other birders.
Though I leaned toward the latter, I was
glad I didn’t have to choose between
them. At our Steamboat convention,
events like the welcome picnic held at
The Nature Conservancy’s Carpenter
Ranch, and the banquet and annual
David Gillilan meeting held at the Colorado Moun-
tain College with expansive views out
over the valley, were just as popular as the dozens of field trips rang-
ing near and far across northwestern Colorado, the keynote address
by Sheri Williamson, and the presentations of scientific papers, all of
which were superb.
Though we continue to experiment with our convention formats,
we expect our next convention, based in eastern Boulder County in
May 2018 (precise venues and dates not yet available), to continue
the trend of mixing people who like birds with birds, and other bird-
ers, and people who study birds! Boulder County provides us with a
variety of good venues to host events, and an opportunity to send
field trips in virtually every direction through a huge range of habi-
tats, from high peaks to the plains and everything in between. It also
gives us a chance to host a convention in an area that has not hosted
the convention since 1987.
Though convention work understandably dominates the thoughts
and time of the CFO board during the first half of the year, I would be
remiss in failing to remind our membership that a great deal of work
is done year-round on a great number of matters, large and small,
by an all-volunteer board, which also serves as its own unpaid staff.
128 Colorado Birds Summer 2017 Vol. 51 No. 3
I would also like to recognize the significant contributions of three
board members who just left the board after many years of hard and
exceptional work: Doug Faulkner, who has served several stints with
CFO as editor of Colorado Birds, CBRC chair, and president; Lisa
Edwards, our membership chair who also did anything and every-
thing else, and could (did?) keep the entire organization functional;
and Ted Floyd, who in the last several years was most likely the one
who communicated to you most of the information you needed to
know about CFO events. We wish them all well, and don’t be at all
surprised if we continue to see more of their handiwork in the future.
On the flip side, the membership voted to bring in three new
board members, Sue Riffe, Jason St. Pierre, and Christy Payne, who
we welcome. Work they’ve already done as volunteers for the Steam-
boat convention has proved them to be a very competent and ener-
getic group. There has been a distinct shift in the demographics of
the board recently, some of it intentional; when I joined the board
just three years ago I could legitimately count myself as being part of
the younger set, notwithstanding that I am older than CFO, and two-
thirds of us, including all four officers, were male. That has changed,
on all counts; today’s officers and board members now look a lot
more like the overall CFO membership in both age and gender. And
though we now have fewer experienced board members (ten current
members came on board within the last three years), I’m confident
that the board still has the people it needs to accomplish CFO’s goals.
Colorado Birds Summer 2017 Vol. 51 No. 3 129
CFO BOARD MEETING MINUTES
4 February 2017
Chatfield State Park
Littleton, CO
Chris Owens
President Doug Faulkner called the meeting to order at 11:11 a.m.
Other officers present included Vice President David Gillilan, Trea-
surer Michael Kiessig, Secretary Chris Owens; directors present were
Mark Peterson, Amber Carver, Gloria Nikolai, Lisa Edwards, Christy
Carello, and Christian Nunes. Guests Larry Modesitt and Buzz Scha-
umberg were also present. Scott Gillihan and Ted Floyd sent their
regrets.
Secretary’s Report: Chris Ow- further discussed after the upcoming
ens’ minutes from the 3 December convention and annual meeting in
2016, meeting were approved with no Steamboat Springs.
changes or additions. Western Field Ornithologists
Treasurer’s report: Treasurer Mi- Partnership: Larry Modesitt, for-
chael Kiessig previously submitted mer CFO BOD member, and current
his report electronically to the board. Western Field Ornithologists, WFO,
Prior to the board meeting, President board member, made a presentation
Doug Faulkner convened a subcom- to the CFO BOD members on the
mittee to go through the Treasurer’s similarities and differences between
budget projections, including conven- WFO and CFO. WE have an official
tion expenses, so as to be in a better partnership with WFO and intend to
position to discuss options and make keep a working relationship. Primar-
recommendations to the full board at ily the differences are in membership
the meeting. The budget projections numbers, convention focus, internal
indicate that CFO continues to be in organizational operations, and money
good financial shape and will maintain making ventures including special
its intended reserve amount, but that events, and membership categories.
recurring expenses for important parts WFO will be hosting their conven-
of CFO’s mission, such as publication tion this fall, 16–20 August 2017, in
of Colorado Birds, maintenance of Pueblo, Colorado. Larry encouraged
three websites, and funding of grants all BOD members to attend. He also
and scholarships, have been going up suggested we work together as partners
and need to be addressed. The focus to encourage members from both or-
at the board meeting was in develop- ganizations to attend both conferenc-
ing different ideas and options that es. WFO hopes to cooperate further
will continue to keep the organization in the coming years since our partner-
in good financial shape, that will be ship is mutually beneficial. CFO will
130 Colorado Birds Summer 2017 Vol. 51 No. 3
update and publish the WFO conven- funds used by CFO throughout the
tion on our website. year to sponsor grants, scholarships,
Least Tern and Piping Plover and other matters. Registration is on
Update from SE Colorado: Doug re- on track for opening in early spring,
ported that there has been a change in and will be online only, as in recent
leadership in the management of the years. Convention information will be
Army Corps of Engineers responsible posted on the Next Convention page
for operations at John Martin Reser- of the CFO website as it is finalized.
voir. This is the area of the state with 2017 Budget: The CFO budget
the biggest population of least terns passed unanimously while meeting
and piping plovers. We are very grate- our cash reserves goal of $25,000.
ful to have had so many years with the
support of the Corps for habitat pro- Committee Reports
tection. CFO acknowledged this by Colorado Birds, the CFO publica-
awarding a Landowner’s Award to the tion: The Winter issue came out on
Corps at the 2016 annual convention time in January. Lisa will work with
in Lamar last May. the printer to see what ways CFO
Succession for Board of Directors could help streamline the printing
Positions: The members leaving have process. We will continue to encour-
been very active in performing various age members to elect to receive the
functions of the board, which means journal in electronic form which will
we will have large shoes to fill, but this help CFO keep costs down. This will
will also provide new opportunities for allow for further funding of operations
continuing and new directors to jump CFO is committed to supporting. The
in with new ideas and become more BOD discussed other costs for pub-
involved in other areas of the board’s lishing the journal and will look to
work. realigning costs in hopes of further
Convention Planning: Conven- reductions.
tion planning has been well under- Membership: Lisa reported that
way for months, but final details and membership is fine with twelve stu-
plans are still being ironed out, mak- dents receiving publications. She is
ing this the start of a very busy part still scanning in past journals having
of the year for board members. Steam- finished the 1960s. She and Doug are
boat is a more expensive venue than splitting the storage of the archived
many that we have used, which has copies.
required some adjustments. The board Publicity: Ted Floyd sent his re-
is pleased to have arranged for lower- grets. He did not report any concerns
cost lodging at the convention venue, and has electronically submitted a
to help hold down expenses for our rough draft of the brochure for the
members, but the board also recog- 2017 convention.
nized the need to adjust some con- Quarterly Field Trips: Doug
vention pricing for the dual purposes Faulkner expects that the usual field
of covering expenses and generating trips will be conducted this year. He
Colorado Birds Summer 2017 Vol. 51 No. 3 131
will inform the BOD if that needs to nominations for awards. The BOD change. He led a discussion about ex- discussed and decided upon the sub- panding opportunities to farther cor- mitted nominations for awards. ners of the state while recalling the Colorado Birds Record Commit- well received trips conducted in the tee (CBRC): Mark Peterson reported Grand Junction area in the past cou- that all members are doing well with ple of years. The BOD discussed some submitted records. He raised a ques- possible leaders. tion about the CBRC bylaws and if Project Grants: Christy Carello there were any changes needed to in- presented summaries of the grants re- corporate Ebird submissions into the quested through her committee. Us- CBRC website and voting structure. ing the stated mission of CFO as our After discussion the BOD decided benchmark for funding projects, the that no changes were necessary and BOD thoroughly discussed the merits the CBRC could continue pursuing of each proposal. Funding awards were more information about Ebird submis- moved and seconded, then passed sions into CBRC. unanimously. Next Meeting: The next BOD Social Media: Christian Nunes re- meeting will take place in Steamboat ported that there are 1767 members Springs on 29 April 2017. on Facebook and it is actively used by Adjournment: President Doug the members. All is going smoothly. Faulkner adjourned the meeting at Awards: Amber Carver presented 4:10 p.m. 132 Colorado Birds Summer 2017 Vol. 51 No. 3
Correction: Birds at Lair o’ the Bear
Park Over the Last Decade
Scott W. Gillihan
Due to an unfortunate error on my part during the editorial pro-
cess, Tables 1 and 2 of Mike Foster’s article in the Spring issue (Foster
2017) omitted some critical information. A corrected version of the
full article has been posted to the CFO website; the missing informa-
tion appears below. My apologies to our readers and to Mike Foster
for the error.
Literature Cited
Foster, M. F. 2017. Birds at Lair o’ the Bear Park over the last decade. Colo-
rado Birds 51:65–78.
These rows were omitted from the bottom of Table 1 (p. 72):
Species Observed Possible Probable Confirmed
Dark-eyed Junco X
Western Tanager FF
Black-headed Grosbeak FL
Lazuli Bunting FL
Common Grackle #
Brown-headed Cowbird FL
Bullock’s Oriole FF
Breeding Codes
O = migrants, nonbreeders at site T = territorial behavior ON = occupied nest
# = in suitable nesting habitat C = courtship, copulation, feeding CF = carrying food
X = < 7 singing males NB - nest building FF = feeding fledgling
M = > 7 or more singing males FL = fledged recently NY = nest with young
P = obvious pair
In Table 2 (pp. 72–74), these 35 species names should have ap-
peared in italics, indicating species for which breeding status is based
on best available information.
Blue-winged Teal Least Flycatcher Sage Thrasher Wilson’s Warbler
Green-winged Teal Hammond’s Flycatcher European Starling Brewer’s Sparrow
Eurasian Collared-Dove Eastern Kingbird House Sparrow Lincoln’s Sparrow
Yellow-billed Cuckoo Red-eyed Vireo Evening Grosbeak White-throated Sparrow
Calliope Hummingbird Bank Swallow Northern Waterthrush Blue Grosbeak
Williamson’s Sapsucker Canyon Wren Common Yellowthroat Western Meadowlark
Red-naped Sapsucker Winter Wren American Redstart Brewer’s Blackbird
American Three-toed Woodpecker Golden-crowned Kinglet Northern Parula Great-tailed Grackle
Willow Flycatcher Brown Thrasher Prairie Warbler
Colorado Birds Summer 2017 Vol. 51 No. 3 133
Summer Observations of Pacific
Wrens Likely Breeding in Colorado
Mike Britten, Jeff Connor, and Kurt Fristrup
On 20 June 2015, while participating in the Rocky Mountain Na-
tional Park (RMNP) “summer solstice bird count,” we (Mike and
Jeff) heard a “stub-tailed wren” singing continually near Calypso Cas-
cades in Wild Basin, Boulder County. The song had a ventriloquial
quality amid the roar of the Calypso Cascades. We were not able to
see the bird well even though we searched for it from 6:30 to 7:00
a.m. MDT. We caught brief glimpses of the bird moving mouse-like
among the moss-covered boulders and downed trees in old-growth,
mixed-conifer habitat. We saw it fly once (to a new singing perch); it
was immediately followed by a second small dark bird that likely was
a second stub-tailed wren.
While neither of us had experience identifying Pacific Wrens
(Troglodytes pacificus), we both thought it was likely a Pacific Wren
because the song was very high pitched, buzzy, and long (5–8 sec-
onds) and sounded similar to Pacific Wren recordings we had heard.
We recorded the song using our smartphone video application and
reported this in the count tally as a probable Pacific Wren.
Mike revisited the site on 23 June 2015 (5:22–7:30 a.m. MDT)
and heard a wren singing constantly from arrival until 7:00 a.m. It
sang once more at 7:15 a.m. During this visit, Mike saw the bird
several times and
had a good look as
it moved along a
large moss-covered
log. It was obvi-
ously a small and
dark stub-tailed
wren. Mike made
several recordings
of the song using
the video capabil-
ity of his camera
(Canon Power-
Shot SX40HS).
Mike revisited
Fig. 1. Photograph of a Pacific Wren (Troglodytes pacificus) the site again on
in Wild Basin in Rocky Mountain National Park, Boulder 28 June 2015; a
County, Colorado.
134 Colorado Birds Summer 2017 Vol. 51 No. 3wren was singing when he arrived
at 5:45 a.m. and sang steadily
through 7:15 a.m., when he left.
Mike finally got very good looks,
took several photos, and made ad-
ditional audio/video recordings.
Overall, the bird was dark ru-
fous brown with darker (almost Fig. 2. Sonogram of a Pacific Wren (Trog-
black) barring, especially under- lodytes pacificus) song in June 2015 in Wild
neath and toward the tail (Fig. 1). Basin, Rocky Mountain National Park,
The wings were barred dark brown Colorado.
(almost black) and rufous buff
color with the buffy barring light-
est on the outer primaries. The tail
was short and barred dark brown
(almost black) and buffy. It had
a single row of small white flecks
just above the wings. The throat
was not distinctly paler than the
Fig. 3. Sonogram of a Pacific Wren (Trog-
rest of the underparts. The bird
lodytes pacificus) song in June 2015 in Wild
had a distinct buffy supercilium.
Basin, Rocky Mountain National Park,
The bill was relatively straight,
Colorado.
short, and brownish (darker above
than below). The eye was dark.
The legs appeared long for the size
of the bird and were flesh colored.
Kurt converted the audio files
into sonograms (Figs. 2 and 3).
We shared the video files, photo-
graphs, and sonograms with Dr.
David Toews, lead author of the Fig. 4. Comparison of the median frequen-
Birds of North America (BNA) cies and frequency ranges of Winter Wrens
species account for Pacific Wren (Troglodytes hiemalis), Pacific Wrens (T.
(Toews and Irwin 2012) and pacificus), and the June 2015 Rocky Moun-
with Dr. Sallie Hejl and Jennifer tain National Park “stub-tailed wren.”
Holmes, two of three coauthors of
the BNA species account for the Winter Wren (Hejl et al. 2002).
All agreed this documentation is consistent with identification of the
Colorado bird as a Pacific Wren.
Kurt performed a cursory quantitative analysis of some Winter and
Pacific Wren songs downloaded from xeno-canto.org to confirm the
expert identifications of the Calypso Cascades wren songs. Measure-
ments of the median and lower and upper quartile frequency values
Colorado Birds Summer 2017 Vol. 51 No. 3 135were extracted from 34 Winter Wren songs, 12 Pacific Wren songs,
and four songs from Calypso Cascades using Raven software (Charif
et al. 2004). Fig. 4 illustrates the unusually high median frequency of
the Calypso Cascades wrens, which is coupled with a relatively low
interquartile bandwidth.
Because this bird was present and singing vigorously on three
separate mornings in the latter half of June, and because we saw two
wrens the first time, we speculated that this was a breeding occur-
rence of Pacific Wrens in Colorado.
Taxonomic History and Occurrence of Winter Wren Subspecies
Until recently, Winter Wrens across the Holarctic were consid-
ered one species, T. hiemalis, with six distinct clades (Drovetski et
al. 2004). Genetic analyses of wrens in an area of British Columbia
(Toews and Irwin 2008), where breeding T. h. hiemalis and T. h. paci-
ficus coexist, concluded that the two North American clades repre-
sent distinct taxa that have been separated for ~4 million years. The
authors saw no genetic evidence of interbreeding in the study area
and proposed that the two taxa, which are very similar in appearance,
maintain genetic separation by singing distinctly different songs and
called them “cryptic species.” Based on this work, the American Or-
nithologists’ Union split Troglodytes wrens into the Pacific Wren (T.
pacificus) of western North America, Winter Wren (T. hiemalis) of
eastern North America, and Northern Wren (T. troglodytes) of Eur-
asia (AOU 2010).
Leukering and Pieplow (2010) use the term “stub-tailed wren”
to refer to unidentified T. hiemalis or T. pacificus wrens in Colorado
and provide information on correctly identifying these taxa based
on plumage and vocalizations. They comment that “A very small
number (near the edge of the foothills.” They noted there are 10 summer re-
cords from the mountains but that they are undocumented and pro-
vided no further information.
We accessed Colorado Bird Records Committee records for T.
pacificus and T. hiemalis (http://coloradobirdrecords.org/ July 2016).
There were 23 reports; 14 were accepted by the Committee. Three
reports were summer reports; one from Brainard Lake west of Ward
(21 June 2000) and two from RMNP (one from Wild Basin [17–25
Table 1. eBird records of Troglodytes pacificus, T. hiemalis, and T. pacificus/hiemalis
in June, July, and August in Colorado.
County Identified as Location Date # Notes
Boulder T. pacificus Lower Wild Basin 7/9/2015 1 "Singing male."
Boulder T. pacificus Rocky Mountain NP--Ouzel Falls 7/7/2015 1 "...foraging and singing…"
Boulder T. pacificus Rocky Mountain NP--Wild Basin area 7/3/2015 1 "Singing at Calypso Cascade"
Boulder T. pacificus Rocky Mountain NP--Wild Basin area 7/10/2015 1
Boulder T. pacificus Rocky Mountain NP--Wild Basin area 7/12/2015 1
Boulder T. pacificus Rocky Mountain NP--Wild Basin area 7/3/2016 1 Singing
Boulder T. pacificus Rocky Mountain NP--Wild Basin area 7/9/2016 1 Singing
Boulder T. pacificus Rocky Mountain NP--Wild Basin area 7/10/2016 1
Boulder T. pacificus Rocky Mountain NP--Wild Basin area 7/12/2016 1
Boulder T. pacificus Rocky Mountain NP--Wild Basin area 7/17/2016 1 Singing
Boulder T. pacificus Rocky Mountain NP--Wild Basin area 7/20/2016 1 Singing
Boulder T. pacificus Rocky Mountain NP--Wild Basin area 7/22/2016 1 Singing
Boulder T. pacificus Rocky Mountain NP--Wild Basin area 7/24/2016 4 Singing bird and "...a female tending
two fledglings."
Boulder T. pacificus/ Rocky Mountain NP--Ouzel Falls 7/2/2014 4 Singing bird with "...three baby wrens
hiemalis right next to it, hopping and creeping
around on a large downed log."
Pitkin T. pacificus/ Snowmass 8/25/1987 1 Note: record from before T. pacificus
hiemalis recognized as a species.
Summit T. pacificus/ Lily Pad Lake trail 8/28/2012 1
hiemalis
Boulder T. hiemalis Calypso Fall/Wild Basin 7/24/2001 1 "Single Wren singing it's heart out."
Note: record from before T. pacificus
recognized as a species.
Boulder T. hiemalis Rocky Mountain NP--Ouzel Falls 7/29/2001 1 Note: record from before T. pacificus
recognized as a species.
Larimer T. hiemalis Rocky Mountain NP--Glacier Gorge/ 7/2/2012 1 "Singing."
Loch Vale
Boulder T. hiemalis Rocky Mountain NP--Ouzel Falls 7/4/2014 1 "Heard singing at very close range."
Colorado Birds Summer 2017 Vol. 51 No. 3 137July 2011] and one from along the trail to Black Lake [2 July 2012]).
These three reports were accepted by the Committee as T. hiemalis.
We downloaded eBird observation records of T. pacificus, T. paci-
ficus/hiemalis, and T. hiemalis for North America on 14 July 2016
(http://ebird.org/ebird/explore). On 24 March 2017 we downloaded
subsequent 2016 T. pacificus observations for Colorado. Table 1 sum-
marizes June, July, and August records for these taxa for Colorado.
Seventeen of the 20 total observations are from the Wild Basin/Ca-
lypso Cascades area in RMNP. Two records include observations of
an adult(s) with fledglings: the 2 July 2014 observation submitted
by Bill Rowe, and the 24 July 2016 record submitted by Christian
Nunes. Another noteworthy record is of a singing T. hiemalis in Gla-
cier Gorge (also in RMNP) about 10 km north-northwest of Calypso
Cascades reported by Kathy Mihm Dunning.
Table 2 summarizes June, July, and August eBird Pacific Wren ob-
servations in Colorado, Arizona, New Mexico, South Dakota, Utah,
and Wyoming through July 2016. These records document breeding
in Arizona (Oak Creek Canyon on the Mogollon Rim), South Dako-
ta (Ward Draw in the Black Hills), and Utah (Wasatch Mountains).
Habitat and Locations for the Pacific Wren
The Wild Basin wren occurred along Cony Creek at Calypso Cas-
cades at approximately 2,774 m elevation. The Creek flows down a
Table 2. eBird records of Pacific Wren (Troglodytes pacificus) in June, July, and
August in Colorado, Arizona, New Mexico, South Dakota, Utah, and Wyoming.
Records retrieved 14 July 2016.
State # unique observations Location(s) Year(s) Notes
CO 13 1 location – Wild Basin, Rocky Mountain NP 2015 These observations are all
from July in the same area.
AZ 4 2 locations – Oak Creek Canyon and Woods 2015 Breeding documented at
Canyon Lake Oak Creek Canyon.
NM 1 1 location – Santa Fe NF 2010 Two birds.
SD 9 4 locations – Ward Draw, Hell Canyon, Long 2007– Breeding documented at
Draw Rd., Pacific Wren Trail 2015 Ward Draw.
UT 21 11 locations – Big Cottonwood Canyon, 1997– Breeding documented at
Millcreek Canyon, City Creek Canyon, Lamb's 2015 several sites.
Canyon, Bowman Fork Trail, Smith and
Morehouse Res., Dry Canyon, SE of Wallsburg,
Noblett's Creek Trail, Teasdale, Zion NP
WY 2 2 locations – Cascade Canyon and Two Ocean 2008,
Lake, Grand Teton NP 2015
138 Colorado Birds Summer 2017 Vol. 51 No. 3steep north-facing slope, creating a loud roar (note the low frequency
noise in the sonograms) even past peak runoff in July. As described
earlier, the area is a jumble of moss-covered boulders and downed
trees and the forest is old-growth, mixed-conifer. The area where we
first heard the bird singing includes a small wetland with standing
water.
In July 2015 Mike also hiked to Black Lake in RMNP, listening
and looking without success for wrens in the area that Dunning re-
ported a singing T. hiemalis on 2 July 2012. The habitat was also old-
growth conifer forest on a north-facing slope with abundant boulders
and downed trees, and with a small stream nearby. Elevation at this
site is ~3,050 m. In 2011, the year before Dunning’s report, a wind
storm caused a massive blowdown, which left few standing trees.
Toews and Irwin (2012) describe T. pacificus use of old-growth
forest structures, including snags, root masses, downed trees, and the
bases of large standing trees for nesting, foraging, and roosting. They
note that this association with old-growth forest is unique among
North American wrens. They also say that breeding territories are
primarily found along rivers and streams (at least in the Pacific coast
range of T. pacificus). They give an elevation range of sea level to
3,788 m (in the Sierra Nevada Mountains, citing Small 1994). The
Wild Basin habitat for Pacific Wrens matches the habitat described
by Toews and Irwin well.
The Utah eBird reports are primarily from the Wasatch Range
east of Salt Lake City (~six canyon locations). There is also a 1 June
1997 report from Teasdale, Utah, and a July report from Zion Na-
tional Park. The South Dakota summer reports are from two or three
locations in the Black Hills (Hell Canyon, Ward Draw, and a general
location just east of Hell Canyon). Three of the Arizona observa-
tions, including a breeding observation, are from Oak Creek Canyon
south of Flagstaff; the only other summer observation from Arizona
is from Wood’s Canyon Lake about 80 km southeast of Oak Creek
Canyon. The two Wyoming summer observations are from Grand
Teton National Park.
Conclusion
It seems likely, based on documentation of stub-tailed wrens over
multiple years that includes observations of singing adults and fledg-
lings, that T. pacificus breeds at Wild Basin in RMNP. It also seems
possible, based on older records of Winter Wrens in summer in Colo-
rado, that there is a small T. pacificus population in the Colorado
Front Range and other ranges breeding in old-growth, mixed-conifer
forest along mountain streams. It is possible that T. pacificus once oc-
Colorado Birds Summer 2017 Vol. 51 No. 3 139cupied a broader range in the interior western United States during
colder times and that the small scattered populations in the Front
Range, Black Hills, Tetons, Wasatch Range, and Mogollon Rim are
relict populations.
The National Audubon Society considers both Winter and Pacific
Wrens as “climate threatened” species (National Audubon Society
2015). Interestingly, the climate suitability models in the Audubon
Society report show slightly increasing climate suitability for Pacific
Wren in summer and winter in the mountains of Colorado, Utah,
and Wyoming from 2000 through 2080. Regardless of model predic-
tions, breeding Pacific Wrens in Colorado may be threatened by rap-
id climate change and related factors (e.g., increased risk of wildfire
in old-growth, mixed-conifer forests).
Acknowledgments
Thanks to Bill Rowe and Tony Leukering for sharing their observations and
knowledge of wrens in Wild Basin and Colorado. Thanks to David Toews,
Sallie Hejl, and Jennifer Holmes for reviewing photographs, movies, and so-
nograms to confirm identification. Thanks also to Jacob Job and Sonya Daw
for helpful comments on the manuscript.
Literature Cited
[AOU] American Ornithologists’ Union. 2010. Fifty-first supplement to the
American Ornithologists’ Union Check-list of North American Birds.
The Auk 127:726–744.
Andrews, R., and R. Righter.1992. Colorado Birds: A Reference to their Dis-
tribution and Habitat. Denver Museum of Natural History, Denver, CO.
Bailey, A. M., and R. J. Niedrach. 1965. Birds of Colorado. Denver Museum
of Natural History, Denver, CO.
Charif, R. A., C. W. Clark, and K. M. Fristrup. 2004. Raven 1.2 User’s Man-
ual. Cornell Laboratory of Ornithology, Ithaca, NY.
Drovetski, S. V., R. M. Zink, S. Rohwer, I. V. Fadeev, E. V. Nesterov, I. Kara-
godin, E. A. Koblik, and Y. A. Red’kin. 2004. Complex biogeographic
history of a Holarctic passerine. Proceedings of the Royal Society B
271(1538). doi:10.1098/rspb.2003.2638.
Hejl, S. J., J. A. Holmes, and D. E. Kroodsma. 2002. Winter Wren (Trog-
lodytes hiemalis), The Birds of North America Online (A. Poole, Ed.).
Cornell Lab of Ornithology, Ithaca, NY. http://bna.birds.cornell.edu/bna/
species/623. doi:10.2173/bna.623.
Leukering, T., and N. Pieplow. 2010. Pacific and Winter Wrens. Colorado
Birds 44:281–286.
National Audubon Society. 2015. Audubon’s Birds and Climate Change Re-
port: A Primer for Practitioners. Version 1.3. National Audubon Society,
New York. http://climate.audubon.org/.
Small, A. 1994. California Birds: Their Status and Distribution. Ibis Publish-
ing, Vista, CA.
140 Colorado Birds Summer 2017 Vol. 51 No. 3Toews, D. P. L., and D. E. Irwin. 2008. Cryptic speciation in a Holarctic pas-
serine revealed by genetic and bioacoustic analyses. Molecular Ecology
17:2691–2705.
Toews, D. P. L., and D. E. Irwin. 2012. Pacific Wren (Troglodytes pacificus),
The Birds of North America Online (A. Poole, Ed.). Cornell Lab of Or-
nithology, Ithaca, NY. http://bna.birds.cornell.edu/bna/species/720.
Mike Britten, Ecologist, National Park Service Rocky Mountain Inventory
and Monitoring Network, Fort Collins, CO
Jeff Connor, Biologist (retired), Rocky Mountain National Park, Estes Park, CO
Kurt Fristrup, Bioacoustical Scientist, National Park Service Natural Sounds
and Night Skies Division, Fort Collins, CO
Colorado Birds Summer 2017 Vol. 51 No. 3 141NEWS FROM THE FIELD
Winter 2016–2017
(December–February)
David Dowell
“News from the Field” contains reports of rare birds found in
Colorado. These reports are compiled from eBird (ebird.org), the
COBirds listserv (cobirds@googlegroups.com), and the West Slope
Birding Network (wsbn@yahoogroups.com). The reports contained
herein are largely unchecked, and the editors do not necessarily
vouch for their authenticity. Species in capitals are those for which
the Colorado Bird Records Committee (CBRC) requests documen-
tation. Please submit your sightings of these “review” species through
the CFO website at coloradobirdrecords.org.
Season Overview
Winter 2016–2017 was warmer than average, resulting in more
ice-free patches on the lakes than usual. Opportunities to view wa-
ter birds produced good numbers of birds and numerous rarities. The
relatively mild weather for winter also might help explain the large
number of warm-season passerines found in Colorado this winter:
Western Kingbird, Blue-gray Gnatcatcher, Eastern Phoebe, Oven-
bird, Grasshopper Sparrow, Chipping Sparrow, Lark Sparrow, Savan-
nah Sparrow, and Bullock’s Oriole.
The star of the show during winter 2016–2017 was a Purple Sand-
piper, found by Jack and Ryan Bushong at Dillon Reservoir in Sum-
mit County. This unusual-looking shorebird breeds in high-latitude
tundra and winters along rocky Atlantic coasts of the US, Canada,
and Europe. This surprise visitor to Colorado made daily appearances
16–31 Dec at its favorite spot in the Blue River inlet of Dillon Reser-
voir, feeding on what appeared to be aquatic worms. This sighting of
Purple Sandpiper represents a new state record, and was species #502
on the Colorado list.
In the list of reports below, county names are italicized, and the fol-
lowing abbreviations are used: CFO – Colorado Field Ornithologists;
CG – campground; DFO – Denver Field Ornithologists; m.ob. – many
observers; NA – Natural Area; NHS – National Historic Site; NP –
National Park; NWR – National Wildlife Refuge; Res. – Reservoir;
SP – State Park; STL – State Trust Lands; SWA – State Wildlife Area.
Greater White-fronted Goose: 1 BRANT (Black): 1 at Hidden /
at Parachute, Garfield, 17 Feb (Vic Mayham Lake (Adams), Aurora Res.
Zerbi); rare for this region. (Arapahoe) and then East Lake Shores
142 Colorado Birds Summer 2017 Vol. 51 No. 3One Tundra Swan and two Trumpeter
Swans, Rice’s Pond at Fountain Creek
Regional Park, El Paso County, during Hooded Merganser, Cherry Creek SP,
the Fountain CBC on 14 Dec 16. Photo Arapahoe County, 3 December 2016.
by Bill Maynard Photo by Todd Deininger
Park (Adams), 13–31 Dec (Chris Ru- 24 Jan (Rick Harner). 2 at Colorado
rik, Meg Reck, Kim Mauritz, m.ob.). 1 River SP, Mesa, 4–18 Feb (Eileen
at Aurora Res., Arapahoe, 15–23 Jan Cunningham, Carol Ortenzio, m.ob.).
(David Blue, Sean Walters, Steven 2 at Jumbo Res., Logan, 12 Feb (Da-
Mlodinow, m.ob.). 1 at Indian Tree vid Dowell, Tim Smart, Joey Kellner,
Golf Course, Jefferson, 26 Jan–3 Mar Kathy Mihm Dunning).
(Doug Faulkner, m.ob.). Tundra Swan: Reports from Arap-
Trumpeter Swan: 2 at Fountain ahoe, Bent, Boulder, Chaffee, Delta,
Creek Regional Park, El Paso, 14–15 Denver, Douglas, El Paso, Jefferson, La
Dec (Ted Floyd, m.ob.). 1 near De- Plata, Larimer, Mesa, Montrose, Mor-
Beque, Mesa, 12–26 Dec (Tom & Kay gan, and Pueblo, 1 Dec–14 Feb.
McConnell, Carol Ortenzio, JoAnn EURASIAN WIGEON: 1 in Ca-
Riggle). 1 at Crown Hill Regional ñon City, Fremont, 7–18 Dec (Mark
Park, Jefferson, 25 Dec (Paul Welsch- Peterson, m.ob.). 1 at Verhoeff Res.,
inger, m.ob.). 1 at Rocky Mountain Bent, 12 Feb (Janeal W. Thompson,
Arsenal NWR, Adams, 26 Dec (Susan Jane Stulp).
Rosine). 1 at Chatfield SP, Douglas, 27 AMERICAN BLACK DUCK: 1
Dec–27 Feb (Jeff Beavers, m.ob.). 2 at Poudre Ponds, Weld, 4 Dec (Steven
near Ovid, Sedgwick, 2 Jan (Sean Wal- Mlodinow, Nick Moore). 1 at Woods
ters, Steven Mlodinow). 1 at Highline Lake, Weld, 25–27 Feb (Steven Mlodi-
Lake SP, Mesa, 31 Dec–2 Jan (Mike now, m.ob.).
Henwood, Denise & Mark Vollmar). Blue-winged Teal: 1 at Verhoeff
1 near Grand Junction, Mesa, 2 Jan Res., Bent, 12 Feb (Jane Stulp, Janeal
(Denise & Mark Vollmar). 2 near W. Thompson). 1 at Belmar Park,
Grand Junction, Mesa, 10 Jan (Diane Jefferson, 28 Feb (Art Hudak, Mark
Trappett). 13 at Browns Park NWR, Chavez).
Moffat, 17–29 Jan (Tresa Moulton, Surf Scoter: 1 at Rocky Mountain
Tom Litteral). 6 near Delta, Delta, Arsenal NWR, Adams, 2 Dec (Mi-
Colorado Birds Summer 2017 Vol. 51 No. 3 143Black Rosy-Finch, Fawn Brook Inn, Al- Leucistic House Finch, Chautauqua lenspark, Boulder County, 27 December Park, Boulder County, 29 December 2016. Photo by David Waltman 2016. Photo by Jane Baryames Lapland Longspur, Chico Basin Ranch, Canyon Towhee, John Martin Reservoir, El Paso County, 12 December 2016. Bent County, 12 December 2016. Pho- Photo by Bill Maynard to by Janeal Thompson Lincoln’s Sparrow, Van’s Grove–Hasty, Swamp Sparrow, Fountain Creek Re- Bent County, 12 December 2016. Pho- gional Park, El Paso County, 2 Decem- to by Janeal Thompson ber 2016. Photo by Bill Maynard 144 Colorado Birds Summer 2017 Vol. 51 No. 3
Scaled Quail, Lamar, Prowers County, Dunlin, McClellan Reservoir, Arapahoe
10 December 2016. Photo by Dave County, 3 February 2017. Photo by
Leatherman Joey Kellner
chael Lanzone, Andrew McGann). Miller, m.ob.). 2 at Cherry Creek SP,
As many as 3 at Aurora Res., Arapa- Arapahoe, 4 Dec (Art Hudak, Mark
hoe, 2–10 Dec, ongoing from Oct Chavez). 1 at Chatfield SP, Jefferson,
and Nov. 1 at Windsor Lake, Weld, 6 Dec, ongoing from Nov. 2 at South
4–5 Dec (Steven Mlodinow, Nick Platte Res., Arapahoe, 8 Dec–6 Jan
Moore). 1 in La Veta, Huerfano, 31 (Diane Roberts, m.ob.). 1 at Sands
Dec (Paul & Polly Neldner, m.ob.). Lake SWA, Chaffee, 11 Dec–19 Jan
White-winged Scoter: As many as (Jack Harlan, Sherrie York, m.ob.). 1
3 at Aurora Res., Arapahoe, 2 Dec–12 at Lowell Ponds SWA, Adams, 3–21
Feb, ongoing from Oct and Nov. Dec (Bob Canter, Gabriel Wiltse).
Black Scoter: 1 at Aurora Res., 1 at Hamilton Res., Larimer, 23 Dec
Arapahoe, 2 Dec, ongoing from Nov. (group led by Nick Komar, m.ob.). 2
3 at Adobe Creek Res., Bent, 3 Dec at Rocky Mountain Arsenal NWR,
(David Dowell). 1 at South Platte Adams, 24 Dec (Peter and William
Res., Arapahoe, 11–26 Dec (Steve VanDyke). 1 at Horsetooth Res., Lar-
Stachowiak, m.ob.). imer, 1–15 Jan (David Dowell, m.ob.).
Long-tailed Duck: 1 at Lake Hasty, 1 at Dry Creek Res., Larimer, 1 Jan
Bent, 23 Nov–2 Dec (Duane Nelson, (David Dowell). 1 at Pueblo Res.,
Janeal Thompson). 1 at Stagecoach Pueblo, 1 Jan–10 Feb (group led by
Res., Routt, 2–4 Dec (JoAnn Riggle, Joey Kellner, m.ob.). 1 at Rueter-Hess
Jason Szyba, m.ob.). 2 at Fossil Creek Res., Douglas, 8–20 Jan (Tim Ryan).
Res., Larimer, 3 Dec (Cynthia Mad- Bufflehead × Common Goldeneye
sen, David Hill, Mary Keithler, Chris (hybrid): 1 in Craig, Moffat, 10 Feb
Goulart, Sue Summers). 1 at Aurora (Jan Leonard).
Res., Arapahoe, 3–31 Dec (Brooke Red-throated Loon: 1 at Valmont
Colorado Birds Summer 2017 Vol. 51 No. 3 145Lesser Black-backed Gull, 2nd cycle, Greater Yellowlegs, private property– Prospect Lake in Memorial Park, Colo- Hasty, Bent County, 8 January 2017. rado Springs, El Paso County, 26 Feb- Photo by Janeal Thompson ruary 17. Photo by Bill Maynard Res., Boulder, 6 Dec (David Dowell, cival, Mark Peterson, Tony Leukering, Christian Nunes). 1 at Chatfield SP, Glenn Walbek, Kathy Mihm Dun- Douglas, 6 Dec (David Suddjian, Lisa ning, m.ob.). 1 at Valmont Res., Boul- Edwards, Loch Kilpatrick). 1 at Pueb- der, 4 Dec–13 Jan (Jeff Parks, m.ob.). lo Res., Pueblo, 10 Dec (Robb Hinds). 1 at Walden Ponds, Boulder, 9 Jan 1 at Highline Lake SP, Mesa, 13–17 (Kim Mauritz). Dec (Kathleen McGinley, Mike Hen- Clark’s Grebe: 1 at Navajo Res., wood, Eileen Cunningham, m.ob.). Archuleta, 22 Feb (Jim Beatty); no pri- 1 at Adobe Creek Res., Kiowa, 5 Feb or winter records in western Colorado. (Steven Mlodinow, David Dowell). Great Egret: 1 near Delta, Delta, Pacific Loon: 1 at Marston Res., 3–16 Dec (Bill Harris, Rick Harner, Denver, 25 Nov–4 Dec (Ira Sanders, Maureen Briggs). 1 at Connected m.ob.). 1 at Pueblo Res., Pueblo, 4 Lakes SP, Mesa, 6 Dec (Maureen Dec, ongoing from Nov. 1 at Valmont Briggs). Res., Boulder, 4–9 Dec (Jeff Parks, Turkey Vulture: 1 in Berthoud, David Dowell). 1 at Aurora Res., Larimer, 4 Feb (Brittany Woiderski). Arapahoe, 10 Dec (Steven Mlodinow, Dunlin: 1 at Cherry Creek SP, Nick Moore). 1 at John Martin Res., Arapahoe, 7 Dec (Art Hudak, Mark Bent, 14–15 Dec (Jane Stulp, Janeal Chavez, m.ob.). 1 at McLellen Res- W. Thompson, Dave Leatherman, ervoir, Arapahoe, 17 Dec (Ed Holub, m.ob.). Thomas Holub, Nelson Ford) and 24 Red-necked Grebe: 1 at Boulder Jan–14 Feb (Gregg Goodrich, m.ob.). Res., Boulder, 28 Oct–6 Dec (Da- 1 at Pueblo Res., Pueblo, 21 Jan–5 Feb vid Dowell, m.ob.). 1 (30 Oct–Feb (Jesse and Renee Casias, m.ob.). 28) and for a while 2 (9–22 Jan) at PURPLE SANDPIPER: 1 at Dil- Pueblo Res., Pueblo (Brandon K. Per- lon Res., Summit, 16–31 Dec (Ryan 146 Colorado Birds Summer 2017 Vol. 51 No. 3
Red-tailed Hawk (Krider’s), Lamar, Bald Eagle, Washington Park, Denver
Prowers County, 22 February 2017. County, 29 January 2017. Photo by
Photo by Dave Leatherman Todd Deininger
and Jack Bushong, m.ob.); first state ICELAND GULL (Iceland /
record. Kumlien’s): 1 adult at Cherry Creek
Baird’s Sandpiper: 1 at John Mar- SP, Arapahoe, 3–5 Dec (Glenn Wal-
tin Res., Bent, 26 Feb (Duane Nelson). bek, Tim Ryan). As many as 2 adults
Least Sandpiper: 2 at Rocky Ford (8 Dec–28 Jan) and 1 first cycle (8–21
SWA, Otero, 30 Jan (Stanley Oswald). Jan) at Aurora Res., Arapahoe (Da-
Long-billed Dowitcher: 2 at Boyd vid Dowell, Kathy Mihm Dunning,
Lake, Larimer, 20 Feb (Mike McCloy, Glenn Walbek, Steven Mlodinow,
Andy Bankert). 2 at Pueblo Chemical Nick Moore, m.ob.). 1 first cycle at
Depot, Pueblo, 22 Feb (Clark Jones). Horsetooth Res., Larimer, 30 Dec
AMERICAN WOODCOCK: (David Dowell). 1 (1 Jan) and then 3
2 (8–11 Jan) and then 1 (13 Jan–28 (3 Jan) first cycle at Larimer County
Feb) at Bobcat Ridge NA, Larimer, 8 Landfill, Larimer (Nick Komar, Sean
Jan (David Wade, Cole Wild, m.ob.); Walters, Tom Thomson, David Dow-
third winter in a row for American ell, Steven Mlodinow). 1 first cycle
Woodcock at this location. at Big Johnson Res., El Paso, 11 Jan
Spotted Sandpiper: Reports from (Mark Peterson). 1 adult at Prewitt
10 different locations in Adams, Arap- Res., Washington, 12 Feb (Joey Kell-
ahoe, Archuleta, Douglas, Garfield, La ner, Tim Smart, Kathy Mihm Dun-
Plata, Mesa, and Pueblo, 2 Dec–18 Feb. ning, David Dowell). 1 first cycle at
Franklin’s Gull: 1 at Horsetooth Horseshoe Res., Larimer, 26–28 Feb
Res., Larimer, 14 Jan (Nick Komar, (David Dowell, David Wade). 1 adult
David Wade). at Woods Lake, Weld, 25 Feb (Steven
California Gull: 1 at Ridgway Res., Mlodinow).
Ouray, 11 Jan (Kathy Mihm Dun- GLAUCOUS-WINGED GULL:
ning); rare for this date and location. 1 first cycle at Larimer County Land-
Colorado Birds Summer 2017 Vol. 51 No. 3 147Red-bellied Woodpecker female, Chico
Ferruginous Hawk, Prowers County, 10 Basin Ranch, El Paso County, 1 Dec
February 2017. Photo by Jane Stulp 16. Photo by Bill Maynard
fill, Larimer, 30 Dec (David Dowell). 3 near Cañon City, Fremont, 30 Dec–1
2 first cycle at Aurora Res., Arapahoe, Jan (Dan Belter, David Tønnessen,
15–28 Jan (Sean Walters, Steven Kara Carragher, Richard Bunn, Mark
Mlodinow, m.ob.). Peterson, Jan Allbright, Lisa Ed-
Great Black-backed Gull: 1 adult, wards).
joined by a second adult 7–12 Jan, at Red-naped Sapsucker: 2 in Du-
Pueblo Res., Pueblo, 18 Nov–26 Feb rango, La Plata, 14 Dec–19 Feb (Kristi
(Wendy Wibbens, Brandon Percival, Dranginis, Ryan Votta, Aaron Keller,
Glenn Walbek, Loch Kilpatrick, Amy Dobbins). 1 in Lyons, Boulder,
m.ob.). 1 adult at John Martin Res., 27 Dec–31 Jan (Peter Burke, m.ob.).
Bent, 15 Dec–1 Jan (Mark Peterson, Eastern Phoebe: 1 near Boulder,
Brad Steger, Duane Nelson, Janeal Boulder, 18 Dec (Christian Nunes,
W. Thompson). 1 first cycle at Au- Peter Gent). 1 at South Platte Park,
rora Res., Arapahoe, 22 Dec–5 Feb Arapahoe, 18 Dec and 19 Feb (Ben
(David Dowell, m.ob.). 1 adult at Au- Sampson, Doug Ward).
rora Res., Arapahoe, 13–28 Jan (Glenn Western Kingbird: 1 at Cherry
Walbek, m.ob.). 1 first cycle at Boul- Creek SP, Arapahoe, 25 Feb (Susan
der Res., Boulder, 6 Feb (Ted Floyd). 1 Rosine, Wendy Wibbens).
first cycle at Horseshoe Res., Larimer, PACIFIC WREN: 1 in Durango,
27 Feb–1 Apr (David Wade, m.ob.). La Plata, 19 Jan–8 Feb (Ryan Votta,
Band-tailed Pigeon: 1 at Green m.ob.).
Mountain Falls, Teller, 15–17 Jan Carolina Wren: 1 in Colorado
(Richard Bunn, Jan Allbright). Springs, El Paso, 6 Dec (Jo Romero).
Barn Owl: 1 near Ridgway, Ouray, 1 in Lamar, Prowers, 17 Jan–19 Feb
21 Dec (Kent Nelson); rare for this (Dave Leatherman, m.ob.).
date, location and elevation. Blue-gray Gnatcatcher: 1 at John
White-throated Swift: As many as Martin Res., Bent, 15 Dec (Mark Pe-
148 Colorado Birds Summer 2017 Vol. 51 No. 3White-breasted Nuthatch, Lamar, Prow-
ers County, 14 January 2017. Photo by
Janeal Thompson
Common Raven, Lagerman Reservoir, 11 Nov–11 Dec (Janeal W. Thomp-
Boulder County, 21 January 2017. son, m.ob.).
Photo by Todd Deininger Grasshopper Sparrow: 1 at Chat-
field SP, Douglas / Jefferson, 17 Dec
terson, Brad Steger). 1 in Hotchkiss, (Joey Kellner).
Delta, 1 Jan (Dennis Garrison). 2 at Chipping Sparrow: 1 near Frank-
Brewster’s Ridge, Mesa, 21 Feb (De- town, Douglas, 6 Dec (Hugh Kingery).
nise & Mark Vollmar). Lark Sparrow: 1 at Parker Re-
Varied Thrush: 1 near Sterling, gional Park, Douglas, 3 Dec (Chris
Logan, 20 Dec–2 Jan (William Kaemp- Gilbert).
fer, m.ob.). 1 at Ken Caryl Valley, Jef- Fox Sparrow (Red): 1 in Colorado
ferson, 29 Dec (David Suddjian). Springs, El Paso, 27 Feb (Richard Tay-
Bohemian Waxwing: 200–400 in lor, David Tønnessen, m.ob.).
the Steamboat Springs area including Golden-crowned Sparrow: 1 near
120 at one location, Routt, 14–17 Dec Grand Junction, Mesa, 6 Dec–8 Jan
(Tresa Moulton, Yampa Valley Bird (Carol Ortenzio, m.ob.). 1 at Rocky
Club). 1 in Boulder, Boulder, 19 Dec Ford SWA, Otero, 16 Dec (Kathy
(Mark Chavez). 22 in Allenspark, Mihm Dunning).
Boulder, 28 Dec (Chris Wood, Jessie Harris’s Sparrow: 1 in Craig, Mof-
Barry). 1 at Rocky Mountain NP, Lar- fat, 4–25 Jan (Jan Leonard, Judith
imer, 1 Jan (Sean Walters). Orton, Forrest Luke). 1 in Jeffer-
Ovenbird: 1 at Fort Lyon Wildlife son, Park, 5–28 Jan (John W. Cobb,
Easement, Bent, 15 Dec (Kathy Mihm m.ob.). Other reports from the Front
Dunning, Lisa Edwards). Range and eastern plains.
Palm Warbler: 1 at First Creek Savannah Sparrow: 1 near Boul-
Open Space, Denver, 4 Dec (Todd der, Boulder, 18 Dec and 24 Feb
Deininger). (Christian Nunes, Peter Gent).
Pine Warbler: 1 in Lamar, Prowers, EASTERN MEADOWLARK
Colorado Birds Summer 2017 Vol. 51 No. 3 149Harris’s Sparrow, Colon Orchard, Fre- Golden-crowned Sparrow, Rocky Ford mont County, 18 December 2016 during SWA, Otero County. 16 December Penrose CBC. Photo by Bill Maynard 2016. Photo by Kathy Mihm Dunning Rusty Blackbird, Cherry Creek, Arapa- Ovenbird, Ft. Lyon Wildlife Easement, hoe County, 3 December 2016. Photo Bent County, 15 December 2016. Pho- by Todd Deininger to by Kathy Mihm Dunning Pine Warbler, Willow Valley, Lamar, Yellow-rumped Warbler, Willow Val- Prowers County, 8 December 2016. ley, Lamar, Prowers County, 5 January Photo by Janeal Thompson 2017. Photo by Janeal Thompson 150 Colorado Birds Summer 2017 Vol. 51 No. 3
Marsh Wren, Lamar Community Col- Carolina Wren, Lamar Community Col-
lege, Prowers County, 18 January 2017. lege, Prowers County, 18 January 2017.
Photo by Janeal Thompson Photo by Janeal Thompson
(Lilian’s): 1 at John Martin Res., Ward). 2 in La Veta, Huerfano, 31
Bent, 5 Feb (Steven Mlodinow, David Dec–1 Jan (Dave Silverman, m.ob.).
Dowell). 3 at Wheat Ridge Greenbelt, Jefferson,
Rusty Blackbird: As many as 5 2–7 Jan (Aaron Shipe). As many as 4
at Cherry Creek SP, Arapahoe, 26 near Hudson, Weld, 2–21 Jan (Doug
Nov–11 Dec (Mary Keithler, m.ob.). Shoffner, m.ob.). 1 at Lake Pueblo SP,
As many as 6 at Rocky Mountain Ar- Pueblo, 10 Jan (Brandon K. Percival).
senal NWR, Adams, 1–4 Dec (Brian 3 at Barr Lake SP, Adams, 21 Jan–12
Berry, m.ob.). 1 at Marjorie Perry Na- Feb (Kim Mauritz, George Ho). 2 at
ture Preserve, Arapahoe, 4 Dec (Sunny Cherry Creek Valley Ecological Park,
Bradford). 2 at Valco Ponds SWA, Arapahoe, 10 Feb (Sunny Bradford).
Pueblo, 4–17 Dec (Steve Larson, Loch Bullock’s Oriole: 1 in Boulder, Boul-
Kilpatrick, Glenn Walbek, m.ob.). 1 der, 13–18 Dec (Laura Osborn, m.ob.).
at Adams and Bunker Res., Weld, 27 White-winged Crossbill: 1 at Left
Dec (Taylor Long, Steven Mlodinow, Hand Res., Boulder, 15 Jan (Christian
Chris Wood, Jessie Barry). 1 at South Nunes). 12 at Winter Park Ski Area,
Platte River, Adams, 28 Dec (Doug Grand, 12 Feb (Andy Boyce).
ACKNOWLEDGMENTS
The sightings reported by contributing observers to eBird, COBirds, and the West Slope
Birding Network are greatly appreciated. Volunteer compilers contributed significantly
to this report: Joyce Takamine (COBirds), Jim Beatty (southwest Colorado), Coen Dex-
ter (west), Dave Leatherman, Forrest Luke (northwest), Rich Miller, Brandon Percival,
John Rawinski (San Luis Valley), and David Silverman. Much of the information in this
report was obtained from the eBird Basic Dataset from the Cornell Lab of Ornithology,
Ithaca, New York.
David Dowell, dave1wx@gmail.com
Colorado Birds Summer 2017 Vol. 51 No. 3 151Wilson’s Snipe, Bobcat Ridge Natu-
ral Area, Larimer County, 26 January
2017. Photo by Dave Leatherman Greater Roadrunner, Lake Hasty, Bent
County, 8 February 2017. Photo by Ja-
neal Thompson
Red-tailed Hawk, Boulder County, Barn Owl, Wertz Pond (feedlot), La-
13 January 2017. Photo by Todd mar, Prowers County, 12 February
Deininger 2017. Photo by Janeal Thompson
152 Colorado Birds Summer 2017 Vol. 51 No. 3Eastern Screech-Owl, Ft. Collins, Lar-
imer County, 27 January 2017. Photo
by Dave Leatherman Yellow-bellied Sapsucker, Willow Val-
ley, Lamar, Prowers County, 4 January
2017. Photo by Janeal Thompson
Mountain Chickadee, Chautauqua Ruby-crowned Kinglet, John Martin
Park, Boulder County, 17 February Reservoir, Bent County, 15 December
2017. Photo by Jane Baryames 2016. Photo by Janeal Thompson
Eastern Bluebird, Lamar Community Cedar Waxwing, Boulder, Boulder
College, Prowers County, 11 February County, 24 February 2017. Photo by
2017. Photo by Janeal Thompson Jane Baryames
Colorado Birds Summer 2017 Vol. 51 No. 3 153IN THE SCOPE
Selected Bird Subspecies of Interest
in Colorado: Part 1
Tony Leukering and Steven G. Mlodinow
Birders have long ignored identification to the subspecies level,
but that has changed, with a recent surge of interest. This is likely
driven, in part, by the splitting fever in vogue in avian taxonomy
(leading to the addition of five species to the Colorado list in the
past 15 years!) but undoubtedly also due to enhanced coverage in
popular field guides. An additional cause may be eBird’s (www.
ebird.org) facility for reporting of birds to the subspecies/subspe-
cies group level for some species. Colorado, where three major life
zones converge, is a fantastic place to study subspecies: how they
interact where they meet (including interbreeding), differences in
their habitat choices and migration timing, and other life history
disparities.
Previous “In The Scope” essays have treated this topic in a more
species-focused fashion, primarily from the potential-future-splits
point of view. This essay treats field-identifiable subspecies in a more-
distant fashion with the aim of introducing Colorado’s birders to
some of the amazing variety within species that occur in our state.
While some of these subspecies have potential to be elevated to spe-
Fig. 1 (back cover). This pale beauty is a juvenile Krider’s Red-tailed Hawk, as discerned
by the overall paleness, with relatively little in the way of markings on the head and the white
ground color to the tail. Despite previous decades of little definitive evidence of occurrence in
Colorado, recent years have seen a plethora of reports backed by confirmatory photographs,
most of adults. Smith Point, Chambers Co., TX; 13 November 2012. Photo by Tony Leu-
kering
Fig. 2 (back cover). The depicted flying sprite is an Eastern Blue-gray Gnatcatcher. The most-
easily used plumage feature to differentiate this form from the western subspecies is the extensive
white on the outer rectrices, which extends all the way to the white undertail coverts. On West-
ern Blue-gray, the white does not quite extend to the undertail coverts, resulting in a band of
black separating the coverts from the white of the rectrices. Smith Point, Chambers Co., TX; 7
October 2012. Photo by Tony Leukering
Fig. 3 (back cover). Unlike the form that breeds in Colorado, individuals of the Eastern/
Northern subspecies group of Hermit Thrushes are smaller than Swainson’s Thrushes and have
browner upperparts and more-orange tails. This bird, with its gray flanks, is probably referable
to the western subspecies of the group, euborius, the form of most likely occurrence in the state.
Cape May Point, Cape May Co., NJ; 17 January 2015. Photo by Tony Leukering
154 Colorado Birds Summer 2017 Vol. 51 No. 3cies rank, many do not. The pictures on the back cover of this issue
provide just a few illustrative examples of the variety inherent in
Colorado’s avifauna. This essay is not intended as a thorough treat-
ment of the subject, but as a primer, and a primer that will occur in
this venue in multiple parts, with the species presented in this first
part being chosen for the relative ease in which birders can provide
distributional data and, generally, for the widespread distribution in
the state of the species. In fact, birders can greatly expand upon our
knowledge of subspecies distributions, as we have so many more eyes
in the field than do taxonomists.
Before digging into subspecies, though, we should take a mo-
ment to define what constitutes a subspecies. Many taxonomists
in the late nineteenth century and first half of the twentieth cen-
tury named subspecies on the basis of average differences between
populations under study, resulting in a plethora of subspecies, many
poorly defined or undefinable. Amadon (1949) followed by Mayr et
al. (1953) and Patten and Unitt (2002) attacked this problem with
the somewhat misleadingly named “75% rule.” Depending on what
parameters are chosen, the 75% rule definition means that 90–97%
of the individuals of one population must be distinguishable from the
equivalent percentage of the other population to be considered a sub-
species (Remsen 2010). Many of the earlier classified subspecies are
now placed together in “subspecies groups”—one or more subspecies
of generally similar appearance and differing from other such groups
Fig. 4 (back cover). Red Fox Sparrows are of annual occurrence in Colorado in very small
numbers, being found primarily in late fall and winter. They differ in many respects from the
breeding form, which is generally absent from the state in late fall and winter. The most-readily
discerned plumage differences are the upperparts streaking, the thin wing bars, and the sizable
patches of rufous coloration on the head. However, beware of hybrid Red × Slate-colored Fox
Sparrows, which can show a bewildering mix of characteristics. Cape May Point, Cape May
Co., NJ; 3 January 2014. Photo by Sam Galick
Fig. 5 (back cover). Pink-sided Junco provides one of the treats of junco ogling in Colorado
from mid-fall through mid-spring. This adult (probably a male) shows off its soft gray head and
upperparts contrasting with the extensive pink sides and the black loral area. This subspecies of
Dark-eyed Junco is larger, and sports more white in the tail, than all Colorado juncos other than
White-winged. Lyons, Boulder Co., CO; 31 January 2017. Photo by Steven G. Mlodinow
Fig. 6 (back cover). This immature White-crowned Sparrow, given this excellent view, is read-
ily determined to belong to the Gambel’s subspecies by the pale loral area and orange bill. That
form is a fall through spring visitor to the state from its far-northern breeding range. Virtually
all White-crowned Sparrows in the state in winter are referable to this form. Union Reservoir,
Weld Co., CO; January 2017. Photo by Steven G. Mlodinow
Colorado Birds Summer 2017 Vol. 51 No. 3 155You can also read
