Just a couple thoughts regarding Matt and Darrel's comments.
First, I think that it's a pretty safe bet that the breeding range of Boreal
Owl has not expanded anytime recently. I think Boreal Owls have "always" been
here, as evidenced by a 1902 specimen record from Klamath County. Since Oregon
birders came to understand where and when to look for this species in the
state, they have been reported regularly. Detection issues surely account for
the lack of earlier records.
Second, I think one could probably argue that the frequency of detections of
Swamp Sparrows and Clay-colored Sparrows in Oregon correlates fairly directly
to the ramp-up in the numbers of talented Oregon birders looking for them.
Swamp Sparrows remain a challenge detection wise. If you don't know their call
note, your chances of finding one is pretty remote. The lack of earlier
Clay-colored Sparrow detections (prior to the late 1970s) was probably more of
an ID issue. It has only been over the past 35-40 years that we've had at our
disposal quality ID references that helped us sort out the subtle differences
between immature Chipping, Brewer's and Clay-colored Sparrows. Once we started
getting a few well-documented photos of Clay-coloreds the Oregon birding
community began to recognize that it was a much more likely vagrant to the
state than we previously thought, plus we had a better search image and ID
references.
With many of the birds that we didn't see 30+ years ago, distributions have
changed dramatically. For the most part, the dramatic changes have involved
more southerly species expanding northward, either as breeders/residents (Black
Phoebe, White-tailed Kite, Red-shouldered Hawk) or post-breeding dispersants
(Brown Pelican, Heermann's Gull, Elegant Tern). Offhand I can't think of any
northerly species that has truly expanded its range into Oregon. Incursions of
Elegant Terns were first tied to El Nino events, but now this species seems to
make it to Oregon each fall regardless of water temperatures. This now annual
northbound flight may be to some degree a learned response to late summer
conditions that result in poor food supplies to the south of us. The current
incursion of Black-vented Shearwaters (or at least the scale of it) is a "once
in a lifetime" event so far as we know. How many years will it be before we see
another incursion of this magnitude? That said, the climate changes we are
seeing will continue to drive changes in sea surface temperatures in the
eastern Pacific and this once in a lifetime event may become a regular thing.
Back when Elegant Terns first invaded Oregon (1983) we thought we might be
witnessing a once in a lifetime or once every 20 years event. Back then none of
us (Matt included) thought that within 15 years or so Elegant Terns would be
seen every fall in Oregon.
The northerly (truly boreal) birds that occasionally show up in Oregon are
often connected to late fall/winter irruptions. As suggested by Matt, we really
don't have much of a handle on which source populations are spawning such
incursions. Just yesterday Shawneen, Stefan Schlick and I saw a Mountain
Chickadee on Chetco Point at Brookings. Was this bird merely an elevational
migrant from the nearby Siskiyou Mtns. or did it come from a more northerly or
interior population? Boreal Chickadees are known to irrupt east of the Rockies,
but it doesn't seem to be as much of a western phenomenon. This seems a bit
counter-intuitive given that the irruptions of other finches, grosbeaks, and
chickadees don't seem to differ that much from east to west. I suspect that if
Boreal Chickadee is ever found in Oregon it will be in connection with a
significant irruptive event.
Lastly, I totally concur with Matt on one point and that is that chance favors
the prepared mind. You can't possibly hope to find something out of the
ordinary if you don't know what that thing looks or sounds like. Studying your
field guide listening to vocal recordings on Xeno Canto are the best way to
prepare yourself for a surprise encounter.
Dave Irons
Portland, OR
Date: Mon, 12 Oct 2015 21:03:27 -0700
From: 5hats@xxxxxxxx
To: matthewghunter@xxxxxxxxx
CC: obol@xxxxxxxxxxxxx
Subject: [obol] Re: Boreal Chickadee Question
Matt, Not saying Boreal Chickadee is to be expected in Oregon. BUT, if you
go back thirty years or so, neither were (at that time) regularly wintering
Swamp and Clay-colored Sparrows, breeding range Boreal Owls, nearly annual
Elegant Terns, northbound excursions of Black-vented Shearwater (shoot, they
didn't even exist by that name back then), and a host of other regular to semi
regular birds, some of which, apparently were here all along, as in the case of
the two aforementioned sparrows and the Boreal Owl, and were simply overlooked.
More properly, their particular habitats had been largely overlooked. If
Boreal Chickadee ever does occur in Oregon, it likely will be in some patch of
micro habitat very similar to that in which the species is found further north,
if such habitat exists in the state. Irruptive vagrancy might not be as much
of an issue as the presence of a slice of such habitat yet overlooked. Notice
I did say "might".Darrel
From: "Matthew G Hunter" <matthewghunter@xxxxxxxxx>
To: "obol" <obol@xxxxxxxxxxxxx>
Sent: Monday, October 12, 2015 8:49:35 PM
Subject: [obol] Boreal Chickadee Question
My apologies regarding the delay since the last comment on this topic, but
(I've been preoccupied and...) I'd like to elaborate and encourage some
thinking on this topic, for those interested....
Stefan's view that Boreal Chickadee is "not to be expected" in Oregon is a view
that has been around a long time. The reasoning is understandable, due in large
part to the experience he described (little or no downslope movement near known
populations in N WA). However, these experiences/observations do not and
certainly cannot encompass the universe of possibilities. And, being
inquisitive, and with my bird/forest/ecological research/work/experience, I am
inclined to ask questions and consider the possibilities....
And, before I go further, it might help for me to say, I do not EXPECT to find
Boreal Chickadees in Oregon--in such a way as to be surprised by not finding
them; that's not what I mean. I don't think anyone *expects* Boreal Chickadee
to be found in Oregon, as one might expect Bohemian Waxwings in NE Oregon most
winters.
However, I do expect--meaning I think it is a possibility--that some day, the
environmental conditions will be such that some Boreal Chickadees will make
their way to Oregon... and hopefully (more on that later) be found. There are
several reasons for my view 1) They are not that far away, 2) large-scale fires
may drastically alter their available habitat and may send them searching for a
home, 3) fall/winter "migrations" of Boreal Chickadees occur in other parts of
their range, therefore, I think it is a possibility here. The reasons we have
not yet seen that here could be genetic, environmental, or ???? 4) The source
of fall/winter Boreal Chickadees could be not only from our "western"
populations, but from populations more in the center of their range, or more
northern locales.
And, if I'm wrong--if it never happens--that's okay! My purpose in my original
seed posting was to have some conversation and consider what is going on with
the Chestnut-backed and Mountain Chickadees, and if it might somehow relate to
Boreal Chickadees.
With that in mind, here are a few more things to think about---for anyone
interested in pondering this.
Where did the Chestnut-backed Chickadees come from that were racing down the
Oregon Coast? Chestnut-backed Chickadees are a normal part of our coastal
avifauna, so seeing that species along the coast is not a big deal, but Alan
and I (others?) clearly noticed bands of *traveling* birds, from north to
south: a movement. Is this movement just within Oregon? Does it extend up to
Washington? Canada? Alaska? Have they come down from the neighborhood of Sooty
Fox Sparrows? Have they come from the Canadian Rockies? I don't know. If they
are just from Oregon, is Clatsop County now devoid of CBCHs? If it is a bigger
movement than just within Oregon, ... how big is it? Does it extend to the
range of Boreal Chickadee?
Same questions for the continuing Mountain Chickadee minor invasion of W OR.
This happens every few years to one degree or another. Where are they coming
from? Bend? Washington? Canadian Rockies?
It is the coincident movements of both these species of chickadees--which
surround and intermingle (in broad scale) with the range of Boreal
Chickadee--that led me to consider what might be happening with Boreals as
well. It makes me think, and ask questions.
I remember when I was a young birder I tried to learn the way things ARE,
thinking that things are pretty static in terms of bird ranges, habitat
preferences, bird sounds, etc. As an "older" birder (really just average birder
age) I instead have a sense of how things change over time: bird ranges,
habitat preferences, bird sounds. Now, I watch for how things are CHANGING.
Nature does that.
But ... if a few Boreal Chickadees showed up in Oregon, would Oregon birders
... notice? Perhaps some would. However, In part because of the prevailing view
that Boreal Chickadees are "not to be expected" in Oregon, I think Oregon
birders are mostly unprepared to detect the species should a few of them wander
this way. I can see myself hearing one call and saying ... ah, that's a
Mountain Chickadee, or that's just a grumpy Black-capped Chickadee, one that
got up on the wrong side of the bed, or frankly, not notice at all! Or, what if
I just see one? I could see myself saying ... (if in some high elevation
forest) wow, a Black-capped Chickadee up here? or Gee that Chestnut-backed sure
looked big. This is just what happens when I am unprepared. How 'bout you? Do
you think you could detect one if it was calling in the woods near
you? If you saw one, would you recognize it instantly? Or would you pass right
by it? ...If the day comes that you think you have found a Boreal Chickadee
in Oregon, best thing would be to at least record its call with your cell
phone, and if you can take pictures, all the better.
So, I'm encouraging folks to just take a look at your field guides, browse the
web and look at photos, and listen to some recordings, to gain at least the
beginnings of familiarity with Boreal Chickadee, if you are not already. If
you study a little bit, and practice with photos and recordings on the web (of
course you could go study actual Boreal Chickadees in their usual range as
well), it will increase the likelihood of noticing a different chickadee by
sight and/or sound that you might want to check out more closely. You will also
learn some things about our common chickadees that you may not have paid
attention to before.
Best Regards,
Matt Hunter
Melrose, OR
