41-B-2017 Blackpoll Warbler

STATUS
Accepted
DATE VOTING COMPLETED
1ST ROUND
7-0
HOW MANY OBSERVED?
1, first-fall plumage
DATE SIGHTING OCCURRED
DATE REPORT PREPARED
REPORTER
Carl Lundblad
LOCALITY OF OBSERVATION
University of Idaho Arboretum and Botanical Gardens, Moscow, ID (Latah County)
HABITAT WHERE THE BIRD WAS OBSERVED
Well-manicured botanical garden. The bird was hanging around lilac bushes in an area with a lush lawn, nearby spruces and other conifers, other shrubs including roses and red-osier dogwood. There has been a major hatch of Crane Flies (Tipulidae sp.), which were mostly on and near the level of the lawn and seemed to keep the warblers and other birds foraging low.
SIGHTING DURATION, CONDITIONS, and EQUIPMENT USED
I was birding with my Bushnell Elite 10x43 bincoulars. The bird was mostly hunkered down deep inside a large dense lilac bush. The first couple of glimpses were with the naked eye. Eventually, I had a solid 1-2 second view through binoculars, as the bird came to the outer edge of the bush. 20-30 minutes later, I was crouched down low looking up into the inner part of the same lilac from below. The bird appeared and gave on and off views for 10-15 seconds, as it moved around in the lower stems of the lilac. It was somewhat backlit, but I was only 15-20 feet away. Finally, I had one additional solid view (maybe 2 seconds) as the bird flew up into some adjacent elm trees, perched in the open, and then disappeared into the canopy. 3 solid encounters (plus glimpses) over about 90-100 minutes of patiently waiting on it. The weather was hazy from wildlife smoke, but calm and warm but not yet hot.
DID YOU TAKE NOTES?
Yes, later the same day
DID YOU CONSULT A FIELD GUIDE OR OTHER REFERENCE WORK?
Yes, later the same day
WHICH GUIDE(S) OR REFERENCE(S): DID YOU CONSULT?
I consulted Sibley Guide to Birds (2nd Edition) after taking notes directly into my eBird checklist (after returning home, maybe 2 hours after the sighting)
DESCRIPTION OF THE BIRD(s)
Copied verbatim from my eBird checklist notes:
"A larger chunky warbler, structured like a Setophaga but with a relatively short tail, straight sharp bill. Greenish-yellow above with fine dark streaks on mantle, dark wings with two boldly contrasting white-ish wing bars each. Paler below, washed with pale yellow, fading to white on undertail, and slight blurry gray streaks on upper breast. Dark lines through eyes break up pale yellow eyerings into arcs............Calls were high clear sharp chips, somewhat metallic like an Orange-crowned but stronger and more emphatic."
BEHAVIOR OF THE BIRD(s)
Resting and occasionally foraging deep within the lilac. During my extended view, it appeared to be foraging in the very lower stems of the lilac. I got the impression that it was spending most of its time resting motionlessly inside the lilac and later in the canopy of a "Prospector Elm". I wondered if it had already filled up on Crane Flies and was digesting? Occasionally it would appear on the outer edge/canopy of the lilac. It almost always called once or twice upon becoming active (except during the longer view, when it was silent). It was incredibly hard to see. Eventually it flew up into the canopy of nearby Prospector Elms (calling once or twice), and then again became impossible to see in the upper canopy. I heard it call once or twice more from the tree canopy, maybe 10 minutes later, and that was my last detection of it.
HOW AND WHEN DID YOU POSITIVELY IDENTIFY THE BIRD, AND WHAT CLINCHED THE IDENTIFICATION FOR YOU?
When I saw an overall yellow-ish wabler, with 2 bold white wing bars, white undertail, faintly streaked breast, streaked mantle, and plain face with a dark like through the eye, I immediately suspected the bird was a fall-plumaged Blackpoll. I was mostly concerned with eliminating (each less likely) Pine and Bay-breasted Warblers, which I was satisfactorily able to do.
HOW DID YOU ELIMINATE SIMILAR SPECIES? WHAT WERE THEY?
Pine Warbler was easily eliminated by the streaked mantle, dark wings, and lack of bold yellow spectacles. Bay-breasted was eliminated by the streaked mantle, faintly streaked breast, white undertail, and lack of any warm buffy coloration on the underparts. Magnolia was eliminated by the yellow (rather than gray) head/face and bolder wing bars, among other things. Brighter yellow, overall, than Blackburnian, with yellow head (including crown), plainer face pattern. The bird was a little bit like an Orange-crowned Warbler but with bold wing bars, streaked mantle, and white undertail and lower abdomen. From Tennessee Warbler by bold white wing bars, streaked mantle, and streaked upper breast. I was not able to see any color on the feet, but did not fell it was necessary given the combination of other characters.
WHAT IS YOUR EXPERIENCE WITH THIS (AND SIMILAR) SPECIES?
I've seen small numbers of Blackpolls in the eastern U.S., on their breeding grounds in the Canadian Rockies (in July of this year), and as western vagrants in Arizona, New Mexico, and Nevada. I've seen them in similar (first-fall) plumage in New Mexico and Nevada. I have seen lots of Pine Warblers in the eastern U.S., as a regular winter visitor in New Mexico, and once in Arizona. I have seen only one Bay-breasted Warbler, ever, during winter in New Mexico. My only Bay-breasted was about as dull as they come, but was still distinctively brighter overall with buffy coloration on the flanks and undertail, and a plainer mantle.
DESCRIBE YOUR GENERAL BIRDING EXPERIENCE
Something like 17 years as a serious birder. I generally bird almost every day, and a PhD student studying avian ecology (current M.S. in Wildlife Science), a term-limited former Nevada Bird Records Committee member, and eBird regional reviewer/editor for 5 counties in Nevada and Idaho.
ADDITIONAL INFORMATION (If any)
A Blackpoll was banded on the previous day (Sept. 3) in Boise by the Intermountain Bird Observatory. Another was seen by a reliable observer in Idaho Falls on Sept. 5. The National Weather Service advertised a dramatic shift to northeasterly winds on September 2-4, and these winds seemed to bring with them a lot of birds (and might be expected to deliver eastern species to Idaho), along with thick smoke from Montana wildfires. These good migration conditions were also forecast by Cornell's BirdCast. The first 2 weeks of September are the expected window for this species to pass through Idaho, and it looks like IBO has had runs of multiple Blackpolls over the course of multiple days in previous years, so small "invasions" of this species seem to periodically occur in early September. This species breeds as nearby as Banff National Park in southwest Alberta (or closer), so it's appearance in north Idaho during fall is not that surprising. A Blackpoll was also well documented near Las Vegas, NV on September 4, of this year, and remained for several days (it was reported to be keeping very close to the ground, like my bird).
WERE PHOTO(S), VIDEO, AND/OR AUDIO OBTAINED FROM THIS SIGHTING?
None

FIRST ROUND VOTING:

Cliff Weisse
Accept

Description supports identification of Blackpoll Warbler.

s
Accept

field marks well described and similar warbles eliminated

Doug Ward
Accept

Fall Blackpolls (Setophaga striata) can be very tough, particularly in separating them from similar plumaged Bay-breasted Warblers (S. castanea). The observer noted specifically the key plumage characteristics in making this call in both the general write up, as well as the comparative notes, so am comfortable accepting this record. The only detraction is that they were not able to note leg color clearly, though immature Blackpolls (which I think this bird likely was) don’t always show the distinctive yellow legs and feet of the adults.

Jay Carlisle
Accept

Many key field marks described well

Jon Isacoff
Accept

Accept. Description accurately matches HY Blackpoll and rules out alternates. It is the case that HY Bay-breasted can be notoriously difficult to distinguish (the “Baypoll” problem), as many birds lack virtually any color on the underparts. However, Blackpoll is one of the most common “Eastern” species to appear in fall migration and Bay-breasted is quite a bit less common. The mantle and streaking details are sufficient to rule out Bay-breasted. Very plain, unmarked HY Yellow-rumped’s can look “Baypoll”-like, especially in poor light or at distance. However, the yellow wash across the breast and short tail are both solid field marks to rule out the most common fall migrant warbler.

Dave Trochlell
Accept

I'm convinced. Other similar-looking warblers were very adequately eliminated.

Darren Clark
Accept

Excellent description supports the ID and eliminates similar species.