Date: 4/9/17 12:28 pm
From: Wayne Hoffman <whoffman...>
Subject: [obol] Re: Willamette Valley habitats
Joel -
On your final point, I was not trying to dismiss anything, just to suggest that the study may have been looking at birds in remnants of native habitat rather than typical for the time oak understood.

Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message --------From: Joel Geier <joel.geier...> Date: 4/8/17 8:51 PM (GMT-08:00) To: Wayne Hoffman <whoffman...> Cc: <obol...>, Bruce Newhouse <newhouse...> Subject: [obol] Re: Willamette Valley habitats

Hi Wayne,

These are good comments but now you've put us all on the spot: Can you confess your age? :-)

As for the suspicions raised by your second paragraph (that Richard Eddy might have picked out examples of relatively "natural" habitats within the area around OSC), I wouldn't doubt them.

However we're not well served by studies that dismiss earlier accounts of dominant understory vegetation, just because that vegetation wasn't quantified in the earlier studies. Understory vegetation is where many birds live.


On Sat, 2017-04-08 at 19:59 -0700, Wayne Hoffman wrote:

Hi - 

I grew up in western Oregon - lived southeast of Eugene (Pleasant Hill area) until I was 10 - I remember picking both "Himalayan" and "Evergreen' blackberries, to eat and for pies in my childhood.  I do not have much recollection of prevalence, but they were not hard to find in pickable volumes.

One other thought:  I wonder if Richard Eddy chose his sites because they had native vegetation, and chose to avoid sites with alien berries?  That might have been a logical thing to do, depending on his goals, but if so, we can only conclude that there were enough such sites still around that he could find some, and enough that the warblers were persisting.  The landscape might have already had a major presence of the alien terrorists.


On 4/8/2017 7:06:19 PM, Joel Geier <joel.geier...> wrote:

Hi Bruce (& OBOLites),

Thanks for your informed discussion of Eurasian blackberries and their impacts on bird habitats in the Willamette Valley.

About Franklin and Dyrness (1989), I'm inclined to think that they might just have been disinclined to list one of these invasive species, as I remember Himalaya/Armenian blackberries (along with scotch broom) were quite evident along the I-5 corridor when I passed through on a Greyhound bus in May of 1985, and during my subsequent years of residence in the Puget Sound area.

Anyway I agree that the effects on native bird species must be profound. Looking at the PEERJ paper that Doug Robinson cited, at least three of the species that were common in 1952, but not found in 2013 re-surveys of approximately the same areas, would have been negatively impacted by invasion of Eurasian blackberries in the understory. Specifically:

Nashville Warbler (invasion of native understory)

Chipping Sparrow (ditto)

Northern Rough-winged Swallow (overgrowth of river/creek banks nesting strata by blackberries).

Joel Geier
Camp Adair area north of Corvallis

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