Dennis,

In the Skok drainage, of course, there has been extensive human use
(clearcuts, agricultural development on lower river). However, the folks
who designed the point count were pretty rigorous in placing the stations
in old-growth - to the point of moving stations 100m from the trail
(which to me was moving from one place in the old growth to another,
but...). We heard/saw some other Hermit/Townsend's, just not AT the
stations, DURING the 8-minute count periods. I don't know where the
vireos were. When the USFS folks summarize all of the counts (3 censuses
at each of 4 locations on the Olympic NF), I can post them. It might
make more sense than just looking at MY one-day portion of the project.

My sense of diversity in the old-growth is that overall diversity might
be high, but numbers of individal species tends to be low. In an
earlier seral stage, does not diversity tend to be lower, with larger
numbers of individuals?

If I'm censusing/birding along a riparian zone in the eastern Washington
wheat lands and bunchgrass, I'd expect a lot more species and numbers
than I would when I stand in the open range land or grain fields for 3 or
5 or 8 minutes. Having just run a Breeding Bird Survey route near
Ritzville, I noted hundreds of W Meadowlarks, Horned Larks, and Savannah
Sparrows in the wheat/bunchgrass. Most of the other species were seen/
heard near ranches or lakes/streams with the physical (barns, corrals,
bridges) and vegetative diversity to support them.

Point counts won't necessarily provide the highest counts of All of the
species in a region. They tend to be used to provide an index for
species at a given site/region/biogeographical zone. We're not talking
"Big Day" birding when we go point-count censusing in the old-growth.

Jon. Anderson
Olympia, WA
anderjda at dfw.wa.gov


On Wed, 21 Jun 1995, Dennis Paulson wrote:

> Jon's count really makes the point of the low diversity of migrants on the
> Olympic Peninsula, as I mentioned some time ago. Note that if there
> weren't Swainson's Thrushes and Pacific-slope Flycatchers, there would be
> virtually none. It's amazing to have only a single warbler with that much
> censusing. I have been similarly (un)impressed on several visits. I don't
> know why the peninsula should have such a much lower diversity, weather
> it's related to summer weather, geological and biogeographical history, or
> human use of the area.