[obol] Nashville Warblers everyone?

[David Irons]

Greetings All,

Here in Eugene, I would not call the numbers of Nashville Warblers particularly exceptional.  Skinner Butte often yields day counts of 6-10 birds and at least one or two days each spring 20+ are tallied on the Butte.  Thus far this year there has been one 20-bird day and several where 6-10 Nashvilles were detected.  Traditionally, Nashville Warblers become an increasingly uncommon migrant as one moves north through the Willamette Valley from Eugene.  However, Portland's Mt. Tabor, which gets a similar level of coverage as Skinner Butte sometimes produces counts of 10-12 birds.  

Nashville Warbler is primarily an upslope breeder and their breeding range west of the Rockies barely extends into Canada and essentially ends in the slopes surrounding the Puget Trough west of the Cascades.  In spring, Nashvilles seem to arrive in Oregon via lowland routes, at least early in the season (before May 1st).  Since they don't breed anywhere on the Willamette Valley floor, or in lowland w. Washington, it is presumed that they move upslope to breeding sites after they arrive via lowland valleys. Given the recent stretch of unseasonably cold weather and low snow levels, Nashvilles may be lingering at low elevations longer than normal causing a buildup in areas where they are only transients in most years. In Lane County, Nashville Warbler is a rare local breeder in the foothills of the Coast Range southeast of Eugene and across the Calapooya Divide (separates the Willamette and Umpqua Valleys) but otherwise their breeding range is restricted to the Cascades from about Oakridge (elev. 1200'+) to the east.  The highest densities of breeding Nashvilles generally kick in at about 3000' elevation.  Today, while birding around Fall Creek Res. e. of Lowell, OR I noticed that there was fresh snow in the trees on the slopes just above Oakridge.  I suspect there is still pretty good snow cover in much of the prime Nashville breeding habitat of eastern Lane Co.

An interesting side note, the fall exodus of Nashvilles occurs almost exclusively at high elevations.  Southbound Nashvilles are quite rare at low elevations and there seems to be no post-breeding dispersal into the valleys of western Oregon.

Dave Irons
Eugene, OR 

From: mchar5 at msn.com
To: fschrock at gmail.com; obol at oregonbirdwatch.org
Date: Thu, 1 May 2008 10:48:11 -0700
Subject: Re: [obol] Nashville Warblers everyone?
















Oboler’s,

I don’t know about “the valley” but in the Bear
Creek/Rogue Valley area the numbers of warblers, including Nashville have been
amazing. Countless numbers of Yellow-rumps much beyond past years.
Orange-crowned warblers and Nashvilles have vastly exceeded what is normally
seen at this time of year. At first it was thought it might be the weather
pattern causing them to hold in this valley but with nicer weather the numbers
have increased. But the most noticeable warbler has been Wilson’s. Where
we normally see one or two or none we are literally seeing them by the dozen.
The number of Common yellowthroats has been very high also but it appears their
numbers have tapered off this week. This week vireos in larger numbers than
usual have started to appear.

 

It has been fun to see.

 

Jim Harleman

 



From: obol-bounces at oregonbirdwatch.org
[mailto:obol-bounces at oregonbirdwatch.org] On Behalf Of Floyd Schrock

Sent: Wednesday, April 30, 2008 11:31 PM

To: Oregon Birders

Subject: [obol] Nashville Warblers everyone?



 

Maybe I haven't been paying attention in past years, but it
seems to me we are hearing more than the usual number of spring reports of
Nashville Warblers in "the valley" this year.  I've had two in
the past two days here in McMinnville's Airport Park.  Anyone else
thinking similar thoughts?




======================

Floyd Schrock

McMinnville, Oregon USA

http://empids.blogspot.com/

====================== 







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