[obol] alder flycatchers in Oregon (kinda long, and a little geeky, but no sonograms, I promise)

[Arch McCallum]

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>http://www.surfbirds.com/blogs/mbalame/archives/2007/05/malheur200705.html
>_______________________________________________
>obol mailing list
>obol at lists.oregonstate.edu
>http://lists.oregonstate.edu/mailman/listinfo/obol
>
>To unsubscribe, send a message to:
>obol-leave at lists.oregonstate.edu.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.oregonstate.edu/mailman/private/obol/attachments/20070601/ae5a4df9/attachment.htm