[obol] Blackpolls spring and fall

Fri Jun 1 07:51:03 PDT 2007

Greetings All,

In response to Arch's query about spring v. fall Blackpoll Warblers; the 
Oregon picture is a little murky.  This species was removed from the OBRC 
Review List after the acceptance of 32 records; twenty-two were in Fall, 
nine were in Spring and one involved an apparent nesting pair in July.   
These records suggest that Blackpolls are slightly more than twice as likely 
in Fall as in Spring.  As Alan suggests, the ratio is really a lot more 
heavily skewed towards Fall occurrence.  With just a few exceptions, species 
of warblers that occur in Oregon as vagrants are more likely here in Fall.  
There are more birds moving south than north (due to reproduction) and in a 
high percentage of cases the vagrant individuals are hatch-year birds.

In California, the overwhelming majority of Blackpolls (dozens found each 
year) are detected in Fall along the outer coast.  The California coast is 
more heavily birded generally and there are lots of sites with isolated 
patches of trees on an otherwise treeless coastal plain that create a 
Malheur HQ effect right on the coast.  Migrant and vagrant passerines 
concentrate at these sites raising the likelihood of detection dramatically. 
  Here in Oregon, most of the coastline is heavily forested and there are 
extremely few sites which consistently produce vagrants and fewer still that 
get anything resembling regular coverage.  Point Reyes, north of San 
Francisco, has several patches that consistently produce vagrants and they 
are covered daily during the fall vagrant season.

Prior to about 1980 the majority of Oregon's vagrant warbler (all species) 
reports involved spring birds and most of those were from Malheur, because 
this was where and when the coverage occurred.  There was essentially no 
fall coverage of the Malheur vagrant traps in those days (pre-1980) and 
Oregon birders were making no real effort to find fall vagrants along the 
coast.  As fall coverage of Malheur has increased the number of fall 
Blackpolls has gone up as well.  Barring a major change in our coastal 
landscape, we will continue to be severely challenged in our efforts to sift 
vagrants out of the dense forests that blanket our coastline.  Most Oregon 
reports have come since this species was dropped from the OBRC Review List.

David Fix, who lives in Arcata,CA, can probably give us a more exact number, 
but I think Humboldt Co. averages about 4-8 Blackpolls a year and yet it is 
a very rare spring bird in that county.

Dave Irons
Eugene, OR

>From: Alan Contreras <acontrer at MINDSPRING.COM>
>To: Arch McCallum <archmcc at qwest.net>
>CC: obol <obol at lists.oregonstate.edu>
>Subject: [obol] Blackpolls spring and fall
>Date: Fri, 01 Jun 2007 06:43:50 -0700
>
>Just guessing, I'd say fall blackpoll records in Oregon outnumber spring
>records 10-1 at least.  I have seen one in spring at Malheur.  I have seen
>maybe 8 fall birds, 6 or so at Malheur and two coastal.  I cover the main
>vagrant sites every year in both seasons, except for the south coast.
>
>--
>Alan Contreras
>EUGENE, OREGON
>acontrer at mindspring.com
>
>
>
> > From: Arch McCallum <archmcc at qwest.net>
> > Date: Fri, 01 Jun 2007 06:19:05 -0700
> > To: 'obol' <obol at lists.oregonstate.edu>
> > Subject: Re: [obol] alder flycatchers in Oregon (kinda long, and a  
>little
> > geeky, but no sonograms, I promise)
> >
> > At 07:32 PM 5/31/2007, Larry Mcqueen wrote:
> >> There could be another factor here, which favors song purity in the
> >> east.  Wherever Willows and Alders overlap, the distinctive
> >> characteristics of their songs are well developed, and this has
> >> segregating relevance.   In other parts of the country where
> >> breeding Willows never meet Alder populations, the type of
> >> segregating forces that shaped the two distinctive songs may be
> >> absent in Willow populations, and the more primitive song variants
> >> persist, and some sound much like Alder songs.  There is no need, in
> >> the absence of breeding Alder Flycatchers, for the purity of song
> >> type in the western populations of Willows.
> >>
> >> Just a thought,
> >
> > And an interesting one. Moreover, it's a testable hypothesis. Jim
> > Sedgwick is a USGS biologist who has done a lot of recording of
> > willows in the west, including in Oregon. He published an
> > authoritative paper a few years ago showing that southwestern willow
> > flycatchers (extimus) sing differently from other western willows.
> > While he didn't look at eastern willows in that paper, he did write
> > the BNA account for the whole species. He didn't mention anything in
> > either pub indicating lesser song purity in the west. I think he
> > might have commented if the western songs were unusually variable,
> > because in general empid and other tyrannid songs are amazingly
> > consistent over thousands of miles of range. (remember, these are
> > suboscines, and the songs are not learned-- it is the alder-willow
> > complex that is the source of that statement (work by Don Kroodsma),
> > which may be over-extrapolated when applied to all suboscines) .
> >
> > Anyway, there is a very simple way to distinguish singing Alder from
> > Willow Flycatcher that doesn't require a very good ear. Alder has
> > only one song-type. Willow has three, which they do a pretty good job
> > of alternating. One of the latter, the creet, is very short and quite
> > distinguishable from the other two. A monotonously consistent
> > Traill's is a good bet for an Alder. Even if Willow's song purity is
> > diminished in the west, it's highly unlikely that a local Willow
> > would give up two-thirds of its song repertoire. A Traill's singing
> > with more than one song-type is a very good bet for a Willow. The
> > Zwee-oo call of the willow is a bit like an Alder feebeeo, and is
> > often the only call given by birds with a nest. It wouldn't be likely
> > to be delivered incessantly from an exposed perch, though.
> >
> > It will be really interesting to analyze those recordings.
> >
> > I agree with Randy's comments below in general. Alder Flycatcher is
> > not expected in Oregon on spring migration because it is essentially
> > an eastern species that migrates north first and then
> > west-presumably. (This was documented in a recent paper on Swainson's
> > Thrush, the Alaskan populations go east and winter with the eastern
> > populations.) Least and Yellow-bellied Flycatcher have similar boreal
> > ranges to Alder. On spring migration they are just retracing their
> > post-glacial range expansion, like so many species. But, given the
> > visual difficulty of these species, it wouldn't be too unlikely that
> > a few come through each year and are overlooked. Same for
> > Gray-cheeked Thrush.
> >
> > So here's a question for Dave Irons and others who keep up with such
> > things. How many spring records of Blackpoll Warbler are there? It's
> > an easily identified species that has a range similar to Alder
> > Flycatcher and Gray-cheeked Thrush.
> >
> >
> >
> > It's all fascinating,
> > Arch McCallum
> > Eugene
> >
> >> Larry McQueen
> >>
> >>
> >> Subject: [obol] alder flycatchers in Oregon (kinda long, and a
> >> little geeky,but no sonograms, I promise)
> >>
> >>
> >> Couple of things to do with the recent spate of alder flycatcher
> >> sightings and subsequent discussion:
> >>
> >> I'm fully on board with questioning the vocal ID of this particular
> >> complex, especially without recordings in hand (they're coming, I
> >> swear).  The two species can make remarkably confusing sounds, but I
> >> wouldn't throw the potential baby out with the bathwater just yet,
> >> and here's why (slightly geeky stuff alert):
> >>
> >> All bird songs exhibit a series of physical characteristics; things
> >> like frequency, cadence, note structure and duration, amplitude,
> >> etc., that taken together, determine how we experience the
> >> sound.  Some of these songs are notoriously difficult to tell
> >> apart.  I think it's useful, though, to parse difficult to separate
> >> bird sounds into two groups: confusing and overlapping.
> >>    * Confusing sounds are those share some, but not all, physical
> >> characteristics.  They are hard to separate because our ears (or
> >> more appropriately, our brains), without a lot of listening
> >> practice, focus on the physical similarities of the sounds instead
> >> of the differences.  Like FITZ bee-you and fee-BEE-oh; the quality
> >> (frequency range and modulation) of the sounds is very similar to
> >> us, leaving a subtle difference in accentuation and syllabism for
> >> separation purposes.
> >>    * Overlapping sounds share so many physical characteristics that
> >> they are, in fact, inseparable by our natural equipment.  At least
> >> most of our equipment; some people are senstive to differences in
> >> physical characteristics of sound that would elude 99.9 % of
> >> us.  Chip notes of some closely related warbler species fall into
> >> this category.
> >>
> >> So why is this distinction relevant?  To my knowledge, when willow
> >> and alder flycatchers are singing their advertising songs, there is
> >> no overlap in the accentuation and syllabism I mentioned
> >> above.  It's consistently different and if both species bred
> >> commonly in Oregon, I'm betting there wouldn't be nearly so much
> >> discussion about potentially confusing the songs.
> >>
> >>  Secondly, I'd be astounded if the lack of Oregon records didn't
> >> reflect the difficulty of IDing them, rather than an actual lack of
> >> occasional occurrence.  Put another way,  I bet they're less rare
> >> than we think they are.  Given alders' long-distance migratory
> >> nature and Oregon's proximity to BC breeding grounds, it would
> >> amaze me if some of those non-vocalizing Traill's flycatchers that
> >> show up in spring weren't sneaky alders.  Most of the other species
> >> that share a boreal breeding range but migrate (generally) east of
> >> the Rockies show up here pretty much annually (I think, but I
> >> obviously don't have a great grip on Oregon bird records
> >> yet!).  The interesting exception may be gray-cheeked thrush,
> >> another skulky bird in a difficult to separate species complex that
> >> probably doesn't sing a great deal on migration.
> >>
> >> cheers,
> >>
> >> randy
> >>
> >> corvallis
> >>
> >>
> >> From: Mike Patterson [mailto:celata at pacifier.com]
> >> Sent: Thu 5/31/2007 12:37 PM
> >> To: obol
> >> Subject: Re: [obol] RBA Alder Fly OREGON CITY
> >>
> >> The "FITZ-bee-oh" (distinctly 3-parted) and "freeBEER" calls
> >> are not unusual around the P-Ranch and are genrally regarded
> >> as Willow Flycatchers.  I have heard the "freeBEER" call in
> >> clearcuts in the Coast Range as well.  Willow Flycatchers are
> >> known for a far more variable repetoire than Alder Flycatcher.
> >>
> >> I recommend that any recordings be sent to one of OBOL's
> >> sonogram masters (I can mke sonograms, but can't analyze them).
> >> I will bet that the recent Alder reports will fall into the
> >> "FITZ-bee-oh" pile rather than the "RAY-bee-oh" pile.
> >>
> >> But as always, I'm willing to be convinced otherwise....
> >>
> >> Tim Rodenkirk wrote:
> >>>
> >>> While jogging south of Benson Pond along the CPR at
> >>> Malheur this past weekend, I heard a flycatcher doing
> >>> a freeBEER call/song that seems identical to what an
> >>> Alder sounds like.  Not the first time I've heard this
> >>> call in Oregon.  I promptly forgot about it, thinking
> >>> it would be an impossible record to get by OBRC.
> >>> Also, I'm not convinced they can't sound similar- but
> >>> I'm no expert. I heard the bird on 5/24 maybe a tenth
> >>> of a mile or south of Benson Pond on the CPR- maybe
> >>> the bird is still around?  I did not stop to observe
> >>> it, figuring it was just another Trail's Flycatcher.
> >>>
> >>> Tim R
> >>> Coos Bay
> >>> off to Alder Flycatcher country in a few weeks
> >>>
> >>
> >> --
> >> Mike Patterson
> >> Astoria, OR
> >> celata at pacifier.com
> >>
> >> Malheur NWR Photo Essay
> >> 
><http://www.surfbirds.com/blogs/mbalame/archives/2007/05/malheur200705.html>h
> >> 
>ttp://www.surfbirds.com/blogs/mbalame/archives/2007/05/malheur200705.html
> >> _______________________________________________
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> >>
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