[obol] Linn county Brewer's Sparrows

[bob altman]

I would agree completely with Dave Iron's assessment about the
likelihood of nesting Brewer's Sparrows at Belt's Road.  Interestingly,
I made two short visits (about 10-15 minutes each time at around 10 am
in the morning) to the site in June and did not hear Brewer's Sparrows,
however, I also did not hear Grasshopper Sparrows or Vesper Sparrows on
those visits either, both of which I heard and saw later, so I still
think it is most likely the Brewer's were there as breeders in June.

The Belt's Road site and much of the general "foothills" area from
Brownsville south to Coburg Hills and west to where the grass seed
fields start harbors probably the best remnant populations of the
grassland bird complex of meadowlark, vesper, and grasshopper sparrows
in the Willamette Valley based on surveys I did there for ODFW and
others back in the mid 90s.  Many of the sites of course are on private
lands far enough away from roads where the birds cannot be heard, but I
was able to get permission to walk on many of them.  The "remnant"
populations of those three species seem to be there because of the
"remnant" habitat that exists - lightly to moderately grazed pastureland
or fallow, agriculturally-inactive "fields."  

When I was first wandering around this area in the mid 90s, I took a
group of biologists down to Belts Road, and a couple of the folks who
were near retirement looked out at the land north of Belts Roads and
commented that this was what much of the Willamette Valley looked like
50 years ago when they were growing up, when large family farms and
pastureland were the norm before the agricultural industries dominated
the landscape.

The occurrence of likely nesting Brewer's Sparrows at Belt's Road is
also interesting beyond the issue of a range extension of a desert
species.  It also conincides with a changing habitat at the site that is
actually less favorable for the three grassland birds, and more
favorable for a bird like Brewer's Sparrow which favors shrub cover over
grass-dominant habitat.  In the last 12 years that I have been going to
the site, there has been considerable "filling in" of the grassland with
shrubs and small trees to the point that parts of the west end of the
area are unsuitable for the grassland birds now.  There always used to
be a pair of grasshopper sparrows at that end near the intersection with
Gap Road and that was where meadowlarks were densest, but now it is too
thick with shrubs and trees to support those species.  Without actions
to set back this succession throughout the site, the time is relatively
short for the grassland birds, however, it makes the habitat more
suitable for a species like Brewer's sparrow, for which the habitat
would have been unsuitable 10 years ago.

Just a couple FYIs....

In the next couple months, ODFW is hiring a Willamette Valley grassland
biologist to work with private landowners and public land managers on
the conservation of this habitat with a particular emphasis on the
meadowlark and the other bird species.  So please keep your sightings of
grassland birds in the valley coming forth as I am sure this kind of
information will be critical to support conservation efforts.

Next summer, I am hoping to revisit most/all of the grasshopper sparrow
sites that I found in 95-96 to look at changes that may have occurred,
and will to prepare a long-overdue paper for Oregon Birds on this
species in the Willamette Valley.




Bob Altman
American Bird Conservancy
311 NE Mistletoe
Corvallis, Oregon  97330
541 745-5339
baltman at abcbirds.org


-----Original Message-----
From: obol-bounces at lists.oregonstate.edu
[mailto:obol-bounces at lists.oregonstate.edu] On Behalf Of DAVID IRONS
Sent: Tuesday, July 31, 2007 10:26 PM
To: Randy.Moore at oregonstate.edu; ptsulliv at spiritone.com;
obol at lists.oregonstate.edu
Subject: Re: [obol] Linn county Brewer's Sparrows

Paul, Randy et al.,

I don't believe the Brewer's Sparrows at Belts Rd. "traveled"
(dispersing 
migrants implied) here from some other breeding site.  The birds I saw
at 
Belts Rd. several weeks ago (after Bob Altman's original report) were
all 
adults.  One bird sing incessantly from several perches in a relatively 
small area.  Given the date (late June early July) and this activity I
think 
it is safe to assume the bird was on territory and summering at this
site.  
I saw a total of four adults, two of which appeared paired.  They were
right 
together and one bird (presumably the male sang a couple times).  There
was 
also a lone adult (presumed female) skulking about in the brush below
the 
area where the other territorial male was singing constantly.  If Paul
and 
Carol saw any hatch year birds among the six individuals he reports,
then I 
think it is a good bet that they hatched locally.

The Fern Ridge Brewer's were all hatch year birds. These three included
two 
without tails that were very weak fliers.  I suspect that these birds 
hatched locally given the relatively early detection date.  A few years
back 
Vjera Thompson (then Arnold) heard a Brewer's Sparrow singing from
Fisher 
Butte at the s.e. corner of the Fern Ridge WMA. In recent years,
Brewer's 
Sparrows (adults and juvs.) have been found nearly annually in the same 
small area where the three juvs. appeared this summer.  These juvs. have
now 
remained in the same small area for about two weeks, suggesting to me
that 
they are not dispersing birds from some distant nesting locale.  
Additionally, it seems odd that dispersing birds from the east or
further 
north would show up a the exact same site year after year.

Throughout the Pacific NW this has been an amazing summer for
extralimital 
"desert" sparrows.  Locally, Brewer's Sparrows have been reported from 
Benton, Linn and Lane Counties.  Grasshopper Sparrows (normally limited
to a 
few select sites in the Willamette Valley) have been found at several
new 
sites around Fern Ridge and there have been reports from Benton Co.,
where 
they are quite rare.  East of the mountains, Black-throated Sparrows
have 
been found at numerous sites in Oregon, Washington and Idaho that are
well 
north and east of their historic range.  Whether this is a one year
anomaly 
or the start of a long-term shift in their range remains to be seen.

Unfortunately, the Brewer's Sparrows were not initially detected until
about 
the first of July when singing activity for many passerines is already 
starting to wind down.  I made some efforts to search for Brewer's and 
Grasshopper Sparrows around Eugene in early July and did turn up a new
site 
for Grasshopper Sparrow, but I wonder what I might have found if I'd
started 
in May.  Next year I am already planning to focus a lot of energy
searching 
Lane County sites that are similar to Belts Road (there are quite a few)
in 
an effort to see if perhaps Brewer's Sparrows are a rare local breeder.

Dave Irons
Eugene, OR


>From: "Moore, Randy" <Randy.Moore at oregonstate.edu>
>To: "Paul T. Sullivan" <ptsulliv at spiritone.com>,"obol" 
><obol at lists.oregonstate.edu>
>Subject: Re: [obol] Linn county Brewer's Sparrows
>Date: Tue, 31 Jul 2007 14:27:20 -0700
>
>I think the reason they weren't young chipping sparrows originally (if 
>memory is serving me correctly, which it often doesn't) is that Dave
Irons 
>(Bob Altman?  I can't remember who found them) heard one or more of
them 
>singing, as well as getting a visual.  A person could definitely be 
>forgiven for mistaking a young chipping sparrow for a Brewer's sparrow,
but 
>that song is distinctive!
>
>cheers,
>randy
>Corvallis
>
>________________________________
>
>From: Paul T. Sullivan [mailto:ptsulliv at spiritone.com]
>Sent: Mon 7/30/2007 9:59 PM
>To: obol
>Subject: [obol] Linn county Brewer's Sparrows
>
>
>
>OBOL:
>
>Carol Karlen and I visited Belts Rd. off Gap Rd., south of Brownsville
on
>Sunday morning.  We found the BREWER'S SPARROWS reported earlier.  We
saw 
>at
>least 6 individuals.
>
>When I originally heard the report of this sighting, I wondered why the
>birds were not young Chipping Sparrows rather than Brewer's Sparrows.
>Vagrant young Chipping Sparrows would only have to travel downslope
from
>nearby woods, rather than from more distant birthplaces.  However,
having
>seen the birds, I do believe they are indeed Brewer's Sparrows.  I
still
>wonder how far they traveled to get to Belts Rd.
>
>Good birding,
>
>Paul T. Sullivan
>
>
>
>
>


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