DEBATE OF '98- responsibilities of forest land owners

Don Baccus dhogaza at
Tue Apr 28 17:16:02 EST 1998

In article <6i5hum$hbu$1 at>,  <dwheeler at> wrote:

>But he started out as a small mammal specialist for the Bureau of Land
>Management. It was in this capacity that he did his first study on the
>California Red-backed vole from a proposed clearcut in Northern California in,
>I think, 1973. At that time, the California Red-backed vole was on the
>endangered species list. Maser proved that the vole was a) not rare, b) the
>most abundant animal west of the Cascades, and c) still a major source of food
>for the nso.

OK, a couple of things...

The Cascades run into N CA, of course, but the forests there are a bit
different than our classic Oregon Coast Range old-growth, for instance.

So his results based on a study in N CA doesn't necessarily contradict
Forsman's studies which were conducted in classic wet, western OR

>Later, the nso situation arose with the Audubon Society adding
>its considerable weight.

Well, we (Portland Audubon) and the Seattle chapter were the lead
plaintiffs in the major suit, I admit. :)

>> My specific question regards his claims vis-a-vis the relative importance
>> of flying squirrel and red-backed vole for nso.
>> Eric Forsman's the guy who did the key nso studies.  Johnsgard cites him
>> (1988) as follows:
>> "The most complete analysis of spotted owl foods is that of Forsman, Meslow,
>> and Wight (1984), whose data were based on more than 4,500 identified prey
>> items from 62 pairs in various parts of Oregon.  On both a frequency of
>> occurence and biomass basis the most important single prey species there
>> is the northern flying squirrel...

>In 1984, nso was nearly unknown outside of old-growth forests. Now they are
>known from fairly young (30-45 year old) plantations.

Depends on where.  Redwoods, yes.  N CA Cascades - I've heard conflicting
information.  Classic wet, wetside coniferous forest - breeding, at least,
is still almost unknown except where there's significant old-growth
available.  Or, so the leader of the Oregon State Cooperative Wildlife
Unit's nso project told me two years ago.

>This may affect the
>frequency of voles vs. flying squirrels. I _believe_ flying squirrels are far
>more common East of the Cascades than West.> But since they are nearly
>exclusively noctural (as are the California red-backed vole) they are largely
>unseen during the day. I did have one fly into a pole-barn shiitake shed in
>Washington during the day. I don't know who was more stunned: the squirrel,
>which took quite a bump and wandered around in a daze for several minutes; or
>me, who had never seen one alive before.

>At any rate, I believe it was Maser and Trappe who identified mostly vole adn
>wood rat remains in nso fecal pellets west of the Cascades, and predominantly
>Northern Flying squirrel remains east of the Cascades.

This sounds backwards to me, at least as far as wood rat goes.  Indeed, it's
exactly backwards of Johnsgard (largely based on Forsman's study, which was
the latest available when the book was written).  Wood rat is significant
in more open forests, and indeed is responsible for the success of nso in
2nd growth redwoods, where wood rats find resprouting redwood stumps ideal
for their largish nests.  The rockies were cited by Johnsgard, again a 
drier forest than our classic wet western coniferous forests west of the
Cascades in Oregon.

>> In wet coniferous forests the flying squirrel was the principle prey

he means those west of the Cascades, here.  Forsman's work was done in
these forests, not eastside forests.  I'm not sure exactly where, i.e.
Coast range vs. say the Willamette NF.  

>Thanks for replying Don. I was not familiar with Forsman's work, and now will
>have an excuse to hunt it out.

Forsman's was considered *the* leading authority on nso throughout the 80s. This
is why Johnsgard cites him.  The original work on home ranges in western WA/OR
was done by him.

He's moved on to other things, as I understand it, after all we have a small
army of biologists working on nso these days.

- Don Baccus, Portland OR <dhogaza at>
  Nature photos, on-line guides, at

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